Siemens SIMATIC TIWAY 1 Operation & User’s Manual

UNILINK Host Adapter User Manual Order Number: PPX:TIWAY–8121–2 Manual Assembly Number: 2587871–0045 Second Edition

1–1 USER MANUAL CHAPTER 1 THE UNILINK HOST ADAPTER 1.1 INTRODUCTION The UNILINK Host Adapter, Figure 1–1 is a second generation host computer interface product that allows a host computer to operate and control secondary devices on a TIWAY I network. The UNILINK Host Adapter, also referred to as the “adapter” in this manual, is a hardware and software extension of the original TIWAY I Host Adapter. Figure 1–1 UNILINK Host Adapter

UNILINK HOST ADAPTER 1–2 USER MANUAL 1.2 FEATURES The hardware is composed of the UNILINK Adapter, shown in Figure 1–1, with a plug-in Personality Interface Module (PIM) PPX:500–6224. The PIM, shown in Figure 1–2, contains the software that causes the UNILINK Adapter to operate as the UNILINK Host Adapter. Figure 1–2 Personality Interface Module (PIM) Figure 1–3 illustrates the basic structure of the UNILINK Host Adapter. The corresponding physical features are shown in Figure 1–4. It includes an RS–232–C/RS–423–A compatible host port that supports the Non-Intelligent Terminal Protocol (NITP) used by the original TIWAY I Host Adapter, or the BDLC protocol, an advanced, byte-oriented subset of the HDLC protocol. Also, there are two TIWAY I interface ports and an external I/O point block.

UNILINK HOST ADAPTER 1–3 USER MANUAL Host Computer RS–232–C/RS–423A Host Interface (Command Processor) TIWAY I Interface External Input Point Output Point TIWAY I Network Secondaries UniLink Host Adapter Figure 1–3 UNILINK Host Adapter Block Diagram Port 1 Port 2 Port 3 Port 4 AC NEUT AC LINE GND 1 2 3 4 5 I/O Host Computer Port Power Connections TIWAY I Ports External I/O Points PPX:500–7111, Dual Local Line media ports shown here. Figure 1–4 UNILINK Host Adapter Physical Features

UNILINK HOST ADAPTER 1–4 USER MANUAL The features of the UNILINK Host Adapter include:
The adapter is noise hardened for factory floor use.
There are internal diagnostics tests to check the internal operation when powered-up or reset, and during normal operation. There is also a selectable test mode that is set locally.
The adapter can be reset locally with an internal switch or remotely with a host issued command.
The adapter supports secondary-to-secondary communications without complex host software or additional hardware.
The adapter is backward compatible with TIWAY I Host Adapter software and drivers.
The adapter includes an independent host communications port capable of serial communications at 38.4K baud. This port operates simultaneously with the network ports.
This host port provides an optional advanced host protocol for improved throughput and data integrity. This protocol also allows up to 32 UNILINK Host Adapters to be multidropped (via a modem) from the same host computer RS–232–C/RS–423–A port.
The adapter supports or provides the following TIWAY I features.
The adapter supports the TIWAY I redundant media feature, providing fault tolerant communications in case of a media failure.
The adapter supports communication with multiple network secondary devices concurrently for higher network throughput.
The adapter supports concurrent network request processing. The host computer does not have to wait for a request to complete before issuing another request when using the advanced host communication protocol.
Commands are provided for background data collection. The adapter can be configured to collect data for the host computer by storing the most current data values in internal memory. Another command then retrieves the data.

UNILINK HOST ADAPTER 1–5 USER MANUAL
The adapter is configurable for a variety of applications needs and includes multiple host computer support, allowing several host computers to communicate with the secondary devices on the same TIWAY I network.
The adapter provides transaction statistics collection to aid network performance tuning. 1.3 TYPICAL NETWORK APPLICATIONS Figure 1–5 illustrates a typical single host network managing a process control application. The host computer application directs the secondary devices through the UNILINK Host Adapter and the TIWAY I network. Commands are provided for downloading or uploading data from the host computer to the secondary devices and for checking the status of an individual device. Host Computer UNILINK TIWAY I UniLink Host Adapter ( MHU) RS–232–C/RS–423–A Host Interface Cable Figure 1–5 Single Host Network

UNILINK HOST ADAPTER 1–6 USER MANUAL The flexibility of the UNILINK Host Adapter also provides for multiple hosts as illustrated in Figure 1–6. In addition to the process control application, your main plant system can link to the same network to track work-in-progress, adjust schedule loads for peak efficiency, and collect product cost data. With an additional UNILINK Host Adapter, you can also add a personal computer workstation to the network for statistical quality control or other uses. Host Computer UNILINK UniLink Host Adapter (MHU) Host Computer UNILINK UniLink Host Adapter (MHU) Figure 1–6 Multiple Host Network

UNILINK HOST ADAPTER 1–7 USER MANUAL 1.4 TIWAY I SYSTEM CHARACTERISTICS TIWAY I is a bus structure Local Area Network (LAN) designed for industrial environments. The TIWAY I network connects a series of Texas Instruments Programmable Controllers (P/Cs) and other devices to one or more host computers. With the network, you can obtain, modify or replace data stored in any of the following Siemens products:
SIMATICTI520/SIMATICTI530/ SIMATICTI520C/SIMATICTI530C P/Cs
SIMATICTI560/SIMATICTI565 P/Cs
PM550/PM550C P/Cs
5TI, Series 102, 103 P/Cs
IT–111, IT–121, IT–121A, IT150, and IT–160 Intelligent Tank Transmitters (ITTs) The P/Cs are connected to a TIWAY I network through Network Interface Modules (NIMs). The PM550 P/C can also be connected with a Computer Interface Module (CIM), but it limits the configuration choices. The UNILINK Secondary Adapter is a TIWAY I interface device that allows other devices, such as the following, to be connected to a TIWAY I network.
Robots
Computer numerical controlled machines
Non-SIMATIC programmable controllers
Intelligent instruments
Computer equipment TIWAY I gateways are also available for connecting the Fisher, Foxboro, and Honeywell networks to TIWAY I. However, you cannot use a gateway and a UNILINK Host Adapter in the same TIWAY I network. TIWAY I is designed to satisfy today’s factory requirements for acquiring data and controlling manufacturing processes. It is a noise-hardened serial binary communications network that uses an advanced data link protocol. Series 500 controllers can be connected with PEERLINK for high speed transfer of small amounts of data between controllers. The PEERLINK is a solution for applications where one or more Series 500 controllers are dependent on high speed transfer of data from another Series 500 controller.

UNILINK HOST ADAPTER 1–8 USER MANUAL With appropriate host software, an operator can program, monitor, and control any P/C or other intelligent device on the TIWAY I network from a single location. The importance of the UNILINK Host Adapter is that it provides a communication link between the TIWAY I network and one or more host computers. Figure 1–7 is a diagram representing the various host computers that can be connected to a UNILINK Host Adapter, and the typical devices that can be controlled in a TIWAY I network. PC/ XT/ AT ICC 6000 CVU 5000 IBM DEC DEC TIPC PDP– 11 UniLink Host Adapter Y / X S E R T E S 1 IBM Other M I H I S / M I C R O S NIM 5TI NIM SIMATIC TI520 NIM SIMATIC TI560 NIM SIMATIC TI565 TIWAY I NIM PM550 NIM SIMATIC TI530/ TI530C NIM Int. Tank Xmtr. PEERLINK PEERLINK PEERLINK PEERLINK Gateways Fisher Honeywell Foxboro Others Map Secondary Adapter Robots CNC Int. Scales Other Int. Devices PC/ XT/ AT Figure 1–7 TIWAY I Network You cannot use a UNILINK Host Adapter in a TIWAY I network that also contains a TIWAY I Gateway or Network Control Module (NCM) or a TIWAY I Host Adapter. Chapter 4 provides information on interfacing the adapter to a TIWAY I network.

UNILINK HOST ADAPTER 1–9 USER MANUAL 1.5 INSTALLATION Instructions for installing the UNILINK Adapter and the UNILINK Host Adapter PIM are given in the UNILINK Adapter Installation and Operation Manual (PPX:TIWAY–8106). It provides the electrical and mechanical installation instructions and guidelines for the the UNILINK Host Adapter. Chapter 2 discusses the different operational modes and how they are configured. Chapter 3 discusses the host computer interface port, Port 3, and how to set the dipswitches to establish communications. Chapter 4 discusses the TIWAY I interface ports, Ports 1 and 2, and how setup your network. 1.6 TECHNICAL ASSISTANCE If you need assistance with the installation an operation of this equipment, contact your Siemens Industrial Automation, Inc. distributor or sales agent. If you need assistance in contacting your distributor or sales office in the United States, call 800–964–4114. 1.7 CUSTOMER SERVICE CENTER If you need assistance in placing an order, returning a product, or learning about product availability, contact your Siemens Industrial Automation, Inc. distributor or sales agent. If you need assistance in contacting your distributor or sales office in the United States, call 800–964–4114.

2–1 USER MANUAL CHAPTER 2 OPERATION AND APPLICATION 2.1 INTRODUCTION This chapter provides an introduction to the UNILINK Host Adapter operation and how it can be used in typical applications. You should refer to Chapter 5 for the complete command syntax and to the Glossary for help with any unfamiliar terms. Network planning forms are located in Appendix E, Appendix F, and Appendix G. 2.2 COMMAND PROCESSING The UNILINK Host Adapter commands are a set of functional tools to help you direct network applications. Each command consists of a one-byte command code and one or more parameters as shown in Figure 2–1. Most parameters have default values that were selected to help you quickly install an operational network and expand it with minimal software changes. As your network grows, you can improve network efficiency by redefining the parameters to match your network needs. Figure 2–2 illustrates the relative performance and flexibility gained with using additional commands. Command Code Parameter #1 Parameter #2 Parameter #n Figure 2–1 Command String Structure

UNILINK HOST ADAPTER 2–2 USER MANUAL Performance and Applications Flexibility Basic HIU Commands Mode Independent Commands Configure Adapter Commands Extended HIU Commands Network Manager Commands 



NUMBER OF COMMANDS Figure 2–2 Performance vs Commands Communications between the host computer and the UNILINK Host Adapter are a series of commands and responses as illustrated in Figure 2–3. For every command sent, there will be a response. The response will be one of the following.
An acknowledgment that the command was received
A command response
The ERROR RESPONSE

UNILINK HOST ADAPTER 2–3 USER MANUAL Host Computer UNILINK Host Adapter Commands Responses Secondary Secondary Figure 2–3 Host Computer To UNILINK Host Adapter Communications Commands are checked for errors before they are executed. The ERROR RESPONSE is a special response that returns a code indicating the type of error. If an error is found, the command will not be executed and the ERROR RESPONSE will be returned. The ERROR RESPONSE will also be returned if a network request does not complete within the host command timeout. The possible error codes that may be returned in the ERROR RESPONSE and corrective actions to take are listed in Chapter 6.

UNILINK HOST ADAPTER 2–4 USER MANUAL 2.3 FUNCTIONAL ORGANIZATION AND OPERATING MODES The UNILINK Host Adapter is organized into two primary functions; the Host Interface Unit (HIU) function and the Network Manager (NM) function. An adapter can be configured with one of these functions or they can be combined to form a Master Host Interface Unit (MHIU). The MHIU, HIU, and NM are three of the six configurable operating modes. In addition to the above modes, there are two Emulate Host Adapter (EHA) modes and a Standalone Network Manager (SANM) mode. 2.3.1 Host Interface Unit Function The primary purpose of the Host Interface Unit (HIU) function is to establish communications between the host computer and the secondary devices on a TIWAY I network. The HIU uses the memory in the adapter for macro buffers and to store host-to-secondary statistics as shown in Figure 2–4. Macro buffers are used to store macro commands and responses. Macros provide a method for connecting, disconnecting, or sending a Primitive to a secondary device without delays in host processing. Macros are discussed further in Paragraph 2.10.1. Commands are received from the host computer and checked for validity. Then the host requests are processed and queued to the Network Manager function for routing to the appropriate secondary device. The Master Host Interface Unit (MHIU) mode combines the HIU function and the Network Manager function.

UNILINK HOST ADAPTER 2–5 USER MANUAL HIU Establishes communications Uses memory for: Macro Buffers between the host computer and the secondary devices. (Dynamically allocated) Host–to–Secondary Statistics Figure 2–4 Host Interface Unit Function Part of the statistics memory area is used for a Secondary Log. As commands are issued to connect and disconnect secondaries, the specified secondary address is added or deleted from the Secondary Log and a network request is queued into the Network Manager. In the background, the adapter is continuously collecting statistics on the number of commands processed, transactions completed on the network, and other items. Commands to retrieve these statistics do not require network transactions, but return the information from the appropriate statistical area. The following operating modes include the HIU function.
Master Host Interface Unit (MHIU)
Host Interface Unit (HIU)
Master Host Interface Unit/Emulate Host Adapter (MHIU/EHA)
Host Interface Unit/Emulate Host Adapter (HIU/EHA)

UNILINK HOST ADAPTER 2–6 USER MANUAL 2.3.2 Network Manager Function Acting as the network primary, the Network Manager function is responsible for controlling the message traffic on the TIWAY I network as shown in Figure 2–5. It receives the requests from HIUs and stores them in a NM buffer, routes them to the designated secondary devices, and returns the secondary response to the HIU that issued the request. There can be only one adapter configured with the Network Manager function in any particular TIWAY I network. This function will only process Network Manager commands. These commands control the TIWAY I network operations, return network statistical information and handle the background monitor and redundant media switching operations. All network requests and responses are queued in the Network Manager buffers area. NM Manages the message traffic on the TIWAY I network. Uses memory for: Network Buffers Network Stations Figure 2–5 Network Manager Function

UNILINK HOST ADAPTER 2–7 USER MANUAL The following operational modes include the NM function. However, the MHIU/EHA mode does not provide access to the NM command set.
Master Host Interface Unit (MHIU)
Network Manager (NM)
Standalone Network Manager (SANM)
Master Host Interface Unit/Emulate Host Adapter (MHIU/EHA) 2.3.3 The Master Host Interface Unit Mode The Master Host Interface Unit (MHIU) is a combination of the HIU and NM functions as shown in Figure 2–6. A host computer connected to an MHIU can communicate with secondary devices through the HIU function and control network performance through the NM function. Remember, only one adapter in a TIWAY I network may have the NM function. HIU NM MHIU Figure 2–6 Master Host Interface Unit Diagram

UNILINK HOST ADAPTER 2–8 USER MANUAL 2.3.4 Typical Network Applications Both single and multiple host networks are supported by the UNILINK Host Adapter. Figure 2–7 illustrates a typical single host network which uses an MHIU as the host interface and network manager. Host Com- puter UNILINK TIWAY I UniLink Host Adapter ( MHU) RS–232–C/RS–4 23–A Host Interface Cable Figure 2–7 Typical Single Host Network Multiple host networks can be configured with a variety of adapters in different operating modes as illustrated in Figure 2–8 and Figure 2–9. Since the NM function is not in the same adapter with the HIU function in Figure 2–9, the NM and HIUs can use the total memory resources of the adapters for their respective needs. This could be an advantage in large networks where the additional memory for NM buffers will increase network performance.

UNILINK HOST ADAPTER 2–9 USER MANUAL Host Com- puter UNILINK UniLink Host Adapter (MHU) Host Com- puter UNILINK UniLink Host Adapter (MHU) Figure 2–8 Typical Multiple Host Network Host Com- puter UNILINK (HIU) Host Com- puter UNILINK (HIU) UNILINK Host Com- puter Figure 2–9 NM Network

UNILINK HOST ADAPTER 2–10 USER MANUAL 2.3.5 The Emulate Host Adapter Modes There are two modes available that provide an emulation of the TIWAY I Host Adapter; the MHIU/EHA and the HIU/EHA. These modes are limited to the base command codes 01 through 08, 20, 21, and FC through FF. The POLL command, code 03, is not available in the HIU/EHA mode. Both of these modes will operate with applications software written for the TIWAY I Host Adapter. The MHIU/EHA can directly replace the TIWAY I Host Adapter in single host network applications. However, the MHIU/EHA cannot be used in a multiple host network. The HIU/EHA provides the ability to use TIWAY I Host Adapter software applications in a multiple host network. 2.3.6 The Standalone Network Manager Mode The Standalone Network Manager mode operates independent of any host computer. It controls the TIWAY I network, but cannot accept any host commands to change any performance parameters. You can use this mode to implement a multiple host network using applications software written for the TIWAY I Host Adapter. Only minor changes to the applications software are needed to process the adapter configuration command. A typical network is shown in Figure 2–10. Host Com- puter UNILINK (HIU) Host Com- puter UNILINK (HIU) UNILINK (SANM) Figure 2–10 Standalone NM Network 2.4 TIWAY I HOST SOFTWARE SUPPORT As mentioned in Paragraph 2.3.5, the MHIU/EHA and HIU/EHA modes will operate with the TIWAY I HOST SOFTWARE products. The MHIU and NM modes will also work with this product; however, you must enclose the extended and NM commands in the XPAR subroutine.

UNILINK HOST ADAPTER 2–11 USER MANUAL TIWAY I Host Software can be used with adapters in a multiple host network. However, you must define an HIU address using the XPAR subroutine and the CONFIGURE HIU command, and you cannot use the POLL command.

UNILINK HOST ADAPTER 2–12 USER MANUAL 2.5 SETTING THE OPERATING MODE Each adapter must be configured for one of the six possible operating modes. The mode is configured with the CONFIGURE ADAPTER command with the exception of the Standalone NM mode, which is chosen by setting Positions 9 and 10 of Dipswitch 1 down. The defaults and dipswitch settings are discussed further in Paragraph 2.5.1. There are three configuration commands; the CONFIGURE ADAPTER command, the CONFIGURE HIU command, and the CONFIGURE NM command. 2.5.1 Configuration Defaults and Dipswitch Settings Most of the parameters associated with the configuration commands have default values chosen to help you install an operating host interface with a minimum amount of effort. As your network expands and you gain experience with the advanced commands, you can change the defaults to tailor the network performance to your needs. The adapter has two 10-position dipswitch banks, located behind the front access door as shown in Figure 2–11. Most of the settings on the dipswitches relate to the parameters for the host and TIWAY I ports. However, the setting of Position 9 on Dipswitch 2 determines the default mode value. When Position 9 is up, the adapter will default to an HIU/EHA and when Position 9 is down, the adapter will default to an MHIU/EHA. LEDs Reset Number 2 Number 1 Figure 2–11 Dipswitch Positions The default mode will be chosen when you issue one of the Base HIU commands before issuing the CONFIGURE ADAPTER command. In the later case, the adapter assumes the default mode from the setting of Position 9 on Dipswitch 2 and assumes the EHA mode. This means that after the adapter is reset, if you issue any of commands 01 through 08, the adapter will assume the MHIU/EHA or HIU/EHA mode depending on the setting of Position 9. 2.5.2 The CONFIGURE ADAPTER Command The first command your application software should send is the CONFIGURE ADAPTER command, code 20. The main function of this command is to set the

UNILINK HOST ADAPTER 2–13 USER MANUAL operating mode to the value specified. The only operating mode that can not be set with this command is the Standalone Network Manager (SANM), since it can not accept any host computer commands. Instead, the SANM mode is selected by dipswitch settings described in Chapter 3 and Chapter 4. Each host computer must send this command to its attached UNILINK Host Adapter(s). The mode remains in effect and can not be changed until the adapter is reset. The parameters for this command specify the HIU address, the maximum secondary device address, and the macro memory limit.

UNILINK HOST ADAPTER 2–14 USER MANUAL At any time, your applications software can retrieve the current values for these parameters by issuing the REPORT ADAPTER CONFIGURATION command, code 21. In addition to those parameter values, this command will also return the values of the dipswitch settings and a flag that indicates whether the CONFIGURE ADAPTER command was previously processed. The physical network parameters for the HIU function of an MHIU are not used, but the CONFIGURE ADAPTER command must still be sent to enable the HIUs network interface. 2.5.3 The CONFIGURE HIU Command The CONFIGURE HIU command defines the network parameters for an HIU function and enables the HIUs TIWAY I interface for both an MHIU and an HIU. The options and associated parameters can occur in the command string in any order, but they can not occur twice in the same command. This command can only be issued once and if successful, the command code, 11, will be returned. The REPORT HIU CONFIGURATION command, code 12, will return the values of the dipswitches, HIU Options, and a flag indicating whether the configuration has been performed. 2.5.4 The CONFIGURE NETWORK MANAGER Command The CONFIGURE NETWORK MANAGER command, code 30, defines the operating parameters for the network ports in the NM and MHIU modes and specifies network options such as auto redundant media. Issue the REPORT NETWORK MANAGER CONFIGURATION command, code 31, to retrieve the dipswitch settings and the current values for the Network Manager parameters and to determine if the CONFIGURE NETWORK MANAGER command has been processed. In a multiprocessing environment, the tasks can check the configuration processed flag to determine whether or not they can begin issuing commands to the adapter.

UNILINK HOST ADAPTER 2–15 USER MANUAL 2.5.5 Configuring the Standalone Network Manager The Standalone Network Manager (SANM) mode is configured completely with dipswitch settings. The definition for some of the dipswitch positions is different for this operating mode as shown in Figure 2–12. The SANM mode is selected by defining the host command timeout as zero by setting Positions 9 and 10 of Dipswitch 1 down. The other positions of Dipswitch 1 define the TIWAY I network parameters.
       
 

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 Figure 2–12 Standalone Network Manager Dipswitch Settings

UNILINK HOST ADAPTER 2–16 USER MANUAL Since the SANM cannot accept any NM commands, Positions 1–7 of Dipswitch 2 define certain Network Manager function options normally configured with the CONFIGURE NETWORK MANAGER command. When Position 1 of Dipswitch 2 is up, it selects a one-half second delay after CTS is active. No delay is selected when the dipswitch is down. When Position 2 of Dipswitch 2 is up, all HIUs are given permission to issue a network disconnect (DISC). This permission is granted by the NM function when it initializes the HIU. No HIUs will be given permission to issue a DISC when the dipswitch is down. Positions 3–6 of Dipswitch 2 represent the binary value for the number of NM buffers to assign to an HIU when the HIU is initialized. The number of NM buffers can range from 1 to 16. The actual binary value selected will range from 0000 to 1111 binary where Position 3 is the most significant bit and Position 6 is the least significant bit. The adapter will then add 1 to the binary value to scale the actual range to 1–16. When Position 7 of Dipswitch 2 is up, the NM function will use the redundant media feature that uses both network ports, Ports 1 and 2, to communicate with the secondary devices. 2.5.6 Configuration Summary The general procedure for configuring the adapter follows in the list below. 1. Set the dipswitch positions. 2. Issue the CONFIGURE ADAPTER command. 3. Issue the CONFIGURE NM command. (If this adapter will be an MHIU or a NM) 4. Issue the CONFIGURE HIU command. (If this adapter will be an MHIU or an HIU)

UNILINK HOST ADAPTER 2–17 USER MANUAL 2.6 SPECIAL NETWORK MANAGER FEATURES The adapter provides two special features in the MHIU and NM operating modes. First is the redundant media channels with selectable automatic media channel switching. Second is the background monitor that will bring devices online dynamically. 2.6.1 Redundant Media Channels The adapter provides for two network media channels, Ports 1 and 2, described in more detail in Chapter 4 . You may select to use only one channel or both by specifying the appropriate value in the CONFIGURE NETWORK MANAGER command. Using redundant media increases the mission reliability of the network or the probability that the network will remain operational when a random failure occurs. When first initialized, the adapter will communicate on Channel A or Port 1. Your applications software can then issue the SWITCH CHANNEL command at any time to change the operating channel for one, several, or all secondary devices. The channel can be switched even if the auto redundant media feature is not active; however, if it is active, the Network Manager function will switch the channel back if a failure occurs. Channel B or Port 2 must be available or an ERROR RESPONSE will be returned when you try to issue this command. If the command is accepted, the adapter will return the command code and the channel code. The primary function of redundant media is to provide a second communications path in the event of a failure on the primary path. This can also be used as a maintenance aid by switching all secondaries to the alternate channel so that the main channel can be maintained without completely shutting the network down. Remember, only one media or channel can be transmitting or receiving in a given instance. The auto redundant media feature allows the Network Manager function to automatically switch a secondary device to the opposite channel if communications can no longer continue on the current channel. The secondary device will be switched if it fails to respond consecutively in maximum-retry-count times. The maximum retry count is specified in the CONFIGURE NETWORK MANAGER command and defaults to 3 times. Once the secondary has been switched, the Network Manager function will attempt to communicate again on the new channel up to the maximum retry count. If the secondary responds, communications will continue on this channel. If the secondary fails to respond, the secondary will be logged as off-line and all associated macros will be disabled. All macro response status words will be updated to indicate that the secondary is off-line, and any network requests that were pending will return the ERROR RESPONSE. 2.6.2 Background Monitor Background monitor is a feature of the Network Manager that instructs it to periodically check the link status of each secondary device. This feature is active in the Network Manager function in all but the EHA modes and the SANM mode. The link status information includes the communications status for each channel and for each secondary, whether the secondary is online or

UNILINK HOST ADAPTER 2–18 USER MANUAL offline, and if the secondary is an HIU. The Network Manager normally cycles through the secondary device log and checks to see if there are any outstanding directives or responses. In addition, it will also select one secondary device address per cycle to perform a link status check. The selected secondary address initially begins with secondary number one and continues with the next secondary address number until reaching the maximum secondary address specified in the CONFIGURE ADAPTER command. Background monitoring then starts over again with address one. The current link status determines what action to take when monitoring a device. If the current link status for the selected secondary address is offline, the Network Manager will issue the initialization sequence. If there is no response, the Network Manager will assume that the device is not in the network and will not retry the message. If the device does respond, its status will be updated and if it is an HIU, buffers will be allocated. This means that any time that a valid secondary device is connected to the network, it will be brought online.

UNILINK HOST ADAPTER 2–19 USER MANUAL If the background monitor detects a secondary that went offline and the auto redundant media feature is active, the Network Manager will attempt to contact the secondary on the alternate channel as described in the Redundant Media section above. You can obtain peak performance by consecutively numbering your secondary devices and HIUs, starting with address 01, and by setting the largest secondary device address value in the CONFIGURE ADAPTER command. This will keep the Network Manager from spending time on device addresses that will never exist on the network. Your applications software can request the link status information with the REPORT SECONDARY LINK STATUS command, code 32.

UNILINK HOST ADAPTER 2–20 USER MANUAL 2.7 THE HIU AS A SECONDARY The HIU function appears as a special secondary device to the NM function. In addition to queuing network requests for the NM function to process, the HIU function will respond to TIWAY I Primitives 02 — Machine Status, 03 — Machine Type/Configuration, and 04 — Primitive Format Configuration. The TIWAY I Systems Manual provides more details on the format and use of Primitives. 2.7.1 Primitive 02 Response The Primitive 02 response will be returned as follows (spaces were added for clarity). LLLL 02 HH DD EE FF Where LLLL is the Primitive length, HH will be 00 indicating that it is operational and performing instruction execution, DD will be 01 indicating that the Auxiliary Power Source Status is not available, EE will be 00 indicating that the NIM is operational, FF will be 00 and has no meaning for an HIU.

UNILINK HOST ADAPTER 2–21 USER MANUAL 2.7.2 Primitive 03 Response The Primitive 03 response will be returned as follows. LLLL 03 HH DDDD EEEE FFFF GGGG IIII JJJJ KKKKKKKK Where LLLL is the Primitive length, HH will be 00 indicating that it is operational and performing instruction execution, DDDD will be 007E indicating that the device type is an HIU, EEEE, FFFF, GGGG, IIII, JJJJ will be 0000, KKKKKKKK will be 00000000. 2.7.3 Primitive 04 Response The Primitive 04 response will be returned as follows. LLLL 04 NNNN MM EE FF GG Where LLLL is the Primitive length, NNNN will be 010E and indicates the maximum Primitive length supported, MM, EE, FF, GG will be 00.

UNILINK HOST ADAPTER 2–22 USER MANUAL 2.8 MODE INDEPENDENT OPERATIONS The mode independent commands perform hardware and software resets, and external I/O point operations regardless of the operating modes. 2.8.1 Reset Commands There are two reset commands that can be sent to the UNILINK Host Adapter regardless of the operating mode. The reset commands should be used cautiously because they clear all macros and configuration parameters, and discard any outstanding operations on the network. The first is the SOFT RESET command, code FE. This command causes the adapter to execute a software reset operation. All current TIWAY I operations will be aborted and the adapter will go into a startup state without performing power up diagnostics. The command code will be returned as a response and the reset will begin immediately after sending the response to the host. Your applications software should not issue another command for at least 500 ms. The second reset command is the RESET ADAPTER command, code FF. The reset will begin within one second after the reset command response is returned to the host. Your applications software should allow an additional five second delay before issuing another command to allow the diagnostics to complete. The response to either reset command will not be returned until the adapter is polled when using the host BDLC protocol. Chapter 3 provides more information on host interface protocols.

UNILINK HOST ADAPTER 2–23 USER MANUAL 2.8.2 The External Input/Output Points The UNILINK Adapter provides a single external input point and a single external output point. These two points operate independently and can be used in a variety of applications like a remote “Adapter Good” indicator. For safety critical applications, any external alarms should be hard-wired independently of the P/C. IN OUT UNILINK Host Adapter Panel Lamp 20 – 40 VDC 20 – 36 VAC (RMS) Remote “ADAPTER GOOD” Indicator Figure 2–13 External Input/Output Points Example Application

UNILINK HOST ADAPTER 2–24 USER MANUAL 2.8.2.1 The External Input Point The input point latches a high level. The option parameter of the REPORT EXTERNAL INPUT STATUS command determines when to reset and latch the external input. The values for the command option are: 00 = Read the input, do not reset the latch. 01 = Read the input, then reset the latch. 02 = Reset the latch, then read the input. Options 00 and 01 report whether the “on” condition ever occurred, but not report the current state of the external input point. Option 02, however, reports the instantaneous value of the input and should be used for time dependent applications. The response will be either 00 indicating that the input is off, or 01 indicating that the input is on. The complete specifications for the input point are given in the UNILINK Adapter Installation and Operation Manual (TIWAY–8106). 2.8.2.2 The External Output Point The MODIFY EXTERNAL OUTPUT STATUS command either turns the external output point ON or turns it OFF. The corresponding voltage levels are given in the UNILINK Adapter Installation and Operation Manual (TIWAY–8106). The command code FC, along with either 00 or 01 will respectively turn off or turn on the output point. The adapter will return the command code in response. The initial state of the External Output Point is zero after a reset or power-up. A remote “Adapter Good” lamp can be set up using this point by connecting it to a remote control center panel lamp so that when the host computer applications software issues the MODIFY EXTERNAL OUTPUT STATUS command to turn on the output point, the lamp will light. If a problem occurs that causes the adapter to reset, the lamp will be extinguished.

UNILINK HOST ADAPTER 2–25 USER MANUAL 2.9 BASIC NETWORK OPERATIONS The simplest network operations, in either a single or multiple host network, are performed using the Base HIU commands, codes 1–8. These commands allow you to bring secondary devices online and offline, send data to/from the secondaries, and retrieve basic statistics. However, these commands are direct issue requests, meaning that the host application must wait for the network response before another command can be issued. Paragraph 2.10 discusses how to process multiple outstanding transactions. 2.9.1 Bringing Secondary Devices Online Issue the CONNECT SECONDARY command to bring secondary devices online. This command logically connects one or more secondary devices and allows your applications software to selectively connect the secondary devices on the network. Memory space will be allocated for secondary device statistics the first time that the secondary is connected. This space will remain in use until the adapter is reset. The address value FF hex or 255 decimal has been reserved as a global address that will connect all secondaries up to the largest address value, specified when the adapter was configured. You must be careful when requesting multiple secondary connections. If the responses are not received before the host command timeout, the ERROR RESPONSE will be returned and you will have to issue the READ SECONDARY LOG command to determine which secondaries were connected before the timeout. A successful connection will return the command code and a list of the secondary device addresses that were connected successfully. If no address in the list was connected, the response will be the command code and a 00 address value. NOTE The host computer must wait for the response to be returned for the CONNECT SECONDARY and READ SECONDARY LOG commands before issuing another command, regardless of the adapter operating mode. There can be a long time delay when using the special global address (FF hex).

UNILINK HOST ADAPTER 2–26 USER MANUAL 2.9.2 Sending Data To And From Secondary Devices After the secondary device is connected, your applications software can send TIWAY I Primitives to the secondary with the SEND NETWORK DATA command or the BROADCAST NETWORK DATA TRANSFER command. The TIWAY I Primitives provide control functions such as reading and writing data elements, controlling the operating mode, and testing the status and configuration of the secondary devices. The SEND NETWORK DATA command transfers a TIWAY I Primitive to a specified secondary device. When completed, the adapter will return the command code, the secondary address, and the Primitive response. NOTE The host computer must wait for the response to be returned for the SEND NETWORK DATA and BROADCAST NETWORK DATA commands before issuing another command, regardless of adapter’s operating mode.

UNILINK HOST ADAPTER 2–27 USER MANUAL The BROADCAST NETWORK DATA TRANSFER command will send the Primitive to all logically connected secondary devices on the network and is provided for backward compatibility with the original TIWAY I Host Adapter. The Broadcast/Poll sequence is more efficiently handled with macros discussed in Paragraph 2.10. Unlike the SEND NETWORK DATA command, the responses from the secondaries do not automatically return. If the command is accepted, the command code will be returned, then your applications software MUST issue a POLL command to each secondary to collect the Primitive response. CAUTION You should not issue the BROADCAST NETWORK DATA TRANSFER command if your network contains Intelligent Tank Transmitters (ITTs) as secondary devices or you could loose responses. Also, sending a BROADCAST NETWORK DATA TRANSFER command when your adapter is configured as either an MHIU or an HIU will cause an network HDLC error to be logged even though the information was received. This error will be included in the statistics from the READ SECONDARY DIAGNOSTICS, REPORT HIU STATUS, REPORT NETWORK MANAGER SECONDARY STATISTICS and the REPORT NETWORK MANAGER NETWORK STATISTICS commands. The POLL command can only be used by an adapter configured as an MHIU/EHA, however, the broadcast/poll sequence can be implemented in other operating modes with macros. Example 2–1 is a typical sequence for the broadcast/poll commands.

UNILINK HOST ADAPTER 2–28 USER MANUAL 02 0002 11 00 02 03 01 03 01 0002 11 01 03 02 03 02 0002 11 01 03 03 Issue Broadcast command Accepted response Poll address #1 Address #1 response Poll address #2 Address #2 response Poll remaining addresses Example 2–1 BROADCAST/POLL Example 2.9.3 Retrieving Secondary Statistics The UNILINK Host Adapter maintains network statistics for the logically connected secondaries on the network. This information is not essential for normal operation, but can be useful for identifying problems. The first statistical command is the READ SECONDARY LOG command, code 06. When this command is received, the UNILINK Host Adapter will respond with the command code followed by the list of secondary device addresses that are logically connected. If no secondaries are connected, the list will contain one byte with a value of 00. The second command is the READ SECONDARY DIAGNOSTICS command. This command returns statistical counters for the network HDLC transmissions and errors. Along with the command code and secondary address, there is a reset statistics counters parameter. The counters are not automatically reset when their maximum value is reached. The reset parameter allows your applications software to reset the counters to start a baseline measurement.

UNILINK HOST ADAPTER 2–29 USER MANUAL 2.9.4 Taking Secondary Devices Off-line The DISCONNECT SECONDARIES command performs the opposite function of the CONNECT SECONDARIES command. The secondary devices listed after the command code are logically disconnected and their addresses removed from the secondary log. Again, the special address code FF, instructs the UNILINK Host Adapter to attempt to disconnect all logically connected secondaries. You must be careful when disconnecting more than one secondary device. The command may be aborted if all secondaries are not disconnected before the host command timeout expires and the ERROR RESPONSE will be returned. The normal response returned will be the command code and a list of secondaries that disconnected properly. If none of the addresses in the list were connected, the response will be the command code and a 00 address value. The HIU function must have permission to issue a disconnect to a secondary before the secondary is actually taken offline. If the permission is not granted, the secondary device will be removed from the secondary log, but will remain online. Option–09 of the CONFIGURE NETWORK MANAGER command defines the default for granting this permission by the background monitor. In addition, the ALLOCATE NETWORK MANAGER BUFFERS command can specify the permission. 2.9.5 Retrieving Adapter Statistics The READ ADAPTER DIAGNOSTICS command, code 08, is another aid to identifying processing problems. This command retrieves a list of counters indicating the number of times that each Base HIU command has been processed. This will help build a profile of which commands are processed most often and will indicate possible bottlenecks. Like the counters for the secondary statistics, these counters are not automatically reset when the maximum limit of is reached.

UNILINK HOST ADAPTER 2–30 USER MANUAL 2.10 EXTENDED NETWORK OPERATIONS The Extended HIU (EHIU) commands provide several performance improvement benefits through macros and bandwidth adjustments. 2.10.1 What Are Macros? Normally, when the host computer issues a network request to connect, disconnect, and send data to and from secondary devices, it must wait for the response to be returned. Macros are network requests that are stored and scheduled for independent processing by the HIU function. The HIU function will issue the network request at the proper time and store the response. This frees the host computer to issue other commands and retrieve request responses without the burden of real-time host computer control. The HIU function is free to schedule macro transmissions and collect responses, so that new macro requests can be issued to the NM function while waiting for older ones to complete processing in the secondary devices. This keeps the network efficient and increases data throughput. 2.10.1.1 Configuration Modes Supporting Macros Table 2–1 Configuration Modes Supporting Macros Macros supported? No MHIU EHA No HIU EHA Yes MHIU Yes HIU No NM No NM SA The UNILINK Host Adapter must be configured as either a Master Host Interface Unit or a Host Interface Unit to use the macro feature. These two operating modes accept the extended host commands for defining macros and collecting macro responses. Macros are not supported in the Emulate Host Adapter modes.

UNILINK HOST ADAPTER 2–31 USER MANUAL 2.10.1.2 Repetitive and Non-Repetitive Macros You specify in each macro definition whether the macro should be issued one time or repeated at regular time intervals. Non-repetitive macros are issued once and collect one macro response, functioning much like a direct command. To reissue the non-repetitive macro, your applications software only needs to send the ENABLE/DISABLE MACRO EXECUTION command to enable it, saving the host-to-adapter communications overhead of sending the Primitive data again. Repetitive macros are issued at the specified time intervals with each new macro response replacing the previous response. The macro will be repeated until your applications software sends the ENABLE/DISABLE MACRO EXECUTION command to disable it. Both repetitive and non-repetitive macros are scheduled for processing by the HIU function. The HIU function schedules the requests in the following order: 1. Direct commands for a single secondary device 2. Direct commands for multiple secondary devices 3. Non-repetitive macros 4. Repetitive macros The HIU function queues all requests except the direct commands for single secondaries. A single secondary direct command is given a higher priority and will be sent to the NM function before any of the queued requests. This priority scheme prevents the repetitive macros from using the entire network bandwidth. When the ENABLE/DISABLE MACRO EXECUTION command code is issued, the non-repetitive macros will be sent in the order listed in the command parameters. The provides a method for defining your own execution priority for the non-repetitive macros. Repetitive macros can be used for background data acquisition, freeing the host computer application even further. Each new repetitive macro response is compared to its previous response and if a difference is detected, the exception flag for that macro is set. The host computer application can check the state of the exception flag and act accordingly without the overhead of collecting and comparing the macro responses itself. A Freeze Exception option can be specified when defining the repetitive macros. This option will disable the macro execution when the exception is detected, and freeze the data that caused the exception.

UNILINK HOST ADAPTER 2–32 USER MANUAL 2.10.2 The Parts of a Macro MACRO HEADER MACRO COMMAND BUFFER MACRO RESPONSE BUFFER Figure 2–14 The Parts of a Macro Each macro is stored in a variable length buffer. The macro buffer is referenced by a unique buffer number assigned by the HIU function when the buffer is allocated. This buffer number ranges from 1 to 254 (01 hex to FE hex) so that up to 254 buffers can be allocated, depending on the size of each macro and the amount of memory set aside for the macro buffers. Each macro buffer consists of command and response buffers referenced by the same unique buffer number and a macro header as shown in Figure 2–14. You specify the size of each macro command buffer and its corresponding macro response buffer in the ALLOCATE MACRO BUFFER command. Use the following formula to calculate the number of bytes of memory required for each macro: Macro Memory = 22 Bytes + Macro Command + Macro Response (Header) Buffer Length Buffer Length If this total is an odd number of bytes, add one to make the total count even. The header is a storage area for the macro operating parameters, one of which is the Macro Response Status Word (MRSW). The MRSW is normally a counter that holds the number of times a repetitive macro has been executed. However, if an error or exception occurs, a termination code indicating the cause of the error will be stored there. Send the GATHER MACRO RESPONSE command to get the MRSW value. The header also contains the Source Id and the secondary address associated with the macro, and internally used pointers and flags.

UNILINK HOST ADAPTER 2–33 USER MANUAL The total macro memory requirements can be calculated by summing the memory for each individual macro. For example, suppose that you use one macro to connect secondary #7, another macro to issue a Primitive 45 bytes long expecting a response 30 bytes long, and another macro to disconnect secondary #5. The total memory required for these three macros is: Macro #1, Connect = 22 = 22 22 Macro #2, Primitive = 22 + 45 + 30 = 97(+1) 98 Macro #3, Disconnect = 22 = 22 22


Total Memory Required 142 Bytes Example 2–2 Macro Memory Requirements Host Computer UNILINK TIWAY I UniLink Host Adapter Job Directory Job A Job B Job C Figure 2–15 Host Computer Multiprocessing Application Example

UNILINK HOST ADAPTER 2–34 USER MANUAL The UNILINK Host Adapter also supports multiprocessing in host computer applications through the host assigned Source Identification number. This number associates each host task with corresponding macros, preventing one task from interfering with another’s resources. Up to thirty-two independent host tasks can be in use at any one time, each assigned a unique value, from 1 to 254. The Source ID can also be used in single task environments to group related subtasks and gather their responses. 2.10.3 The Macro Commands Macros are defined and maintained with the following commands.
ALLOCATE SOURCE ID
ALLOCATE MACRO STORAGE BUFFERS
DEFINE MACRO
GATHER MACRO RESPONSE
ENABLE/DISABLE MACRO EXECUTION
INITIALIZE MACRO RESPONSE BUFFER
LINK MACRO

UNILINK HOST ADAPTER 2–35 USER MANUAL 2.10.4 Setting Up A Macro Figure 2–16 flowcharts the steps for setting up macros. Commands for checking available memory are not included in the flowchart, but are described in the sections that follow. Allocate A Source ID Allocate A Macro Buffer Define the Macro More Macros for the same source? 
 (START)  Figure 2–16 Macro Setup Procedure

UNILINK HOST ADAPTER 2–36 USER MANUAL 2.10.4.1 Allocate A Source Identification Number Use the ALLOCATE SOURCE ID command, code 10, to specify a Source Identification number which can range from 1 to 254 (01 to FE hex). Only thirty-two unique Source Identification numbers can be used at any one time. Figure 2–17 illustrates the relationship between Source Ids and macro buffers. Source ID #1 (OE) Source ID #2 (1A) Source ID #32 (E5) Macro Buffer #1 Macro Buffer #35 Macro Buffer #63 Macro Buffer #87 Macro Buffer #2 Macro Buffer #3 Macro Buffer #80 Macro Buffer #97 Macro Buffer #109 Macro Buffer #4 Macro Buffer #33 Macro Buffer #60 Up to 32 unique source IDs Up to 254 Macro Buffers Figure 2–17 Relationship Between Source Ids and Macro Buffers

UNILINK HOST ADAPTER 2–37 USER MANUAL If this command is accepted, the UNILINK Host Adapter will echo back this same command string, otherwise the ERROR RESPONSE will be returned. Source Ids can also be used to group network responses, such as the status of each device. Only one Source Identification number is allocated with each command sent to the UNILINK Host Adapter. WARNING All existing macro buffers for the Source Identification number will be cleared when the ALLOCATE SOURCE ID command is processed. This prevents a task that abnormally terminated from allocating additional resources while the original resources remain allocated, but unused. Make sure that your application programs use unique Source Identification numbers. 2.10.4.2 Allocate The Macro Buffers Use the ALLOCATE MACRO STORAGE BUFFERS command, code 13, to define and specify the length for both the macro command buffer and the macro response buffer. The UNILINK Host Adapter will return the buffer number assigned by the HIU. Store the buffer number in your application program for later reference. If you specify more than one buffer pair in the command, more than one buffer number will be returned in the response. Be sure to allocate a sufficient length of memory for both the macro command buffer and the macro response buffer.

UNILINK HOST ADAPTER 2–38 USER MANUAL 2.10.4.3 Define The Macro Use the DEFINE MACRO command, code 14, to define the macro and the macro options. Figure 2–18 shows the DEFINE MACRO command frame. Macros can connect a secondary, disconnect a secondary, or send a Primitive to a secondary. These three functions are the macro types as shown in Table 2–2. The “connect” and “disconnect” secondary macro types do not require any buffer storage to hold the command, only 22 bytes for the header.         
      Figure 2–18 Macro Command Frame Table 2–2 Macro Types Type Code 01 02 03 Function Performed Send Primitive to secondary Connect the secondary Disconnect the secondary The UNILINK Host Adapter will return the Command Code, the Source Identification number, and the buffer number to indicate that the command was accepted. However, this does not mean that the secondary was actually connected because macros are scheduled for later execution. When the “connect” secondary macro is executed, the MRSW will be set to indicate if the connect was successful or if not, why it failed. The “disconnect” secondary macro type works just like the “connect” secondary type except that the secondary is disconnected rather than connected. Both the “connect” and “disconnect” secondary macro types are automatically enabled for execution when the command is accepted from the host computer.

UNILINK HOST ADAPTER 2–39 USER MANUAL The third macro type is “send Primitive” which is functionally equivalent to using the SEND NETWORK DATA command, but is far more flexible. This macro begins with the same bytes as the two other types with the addition of a macro options byte, a minimum reissue delay time word, and the Primitive data. The macro options byte uses its five most significant bits to enable or disable the following options.
The auto enable option which specifies whether to automatically enable the macro for execution after definition is complete or not. If you do not choose this option, you can explicitly enable the macro with the ENABLE/DISABLE MACRO EXECUTION command.
The repetitive/non-repetitive option which defines how the macro will be executed.
The freeze option which selects whether to freeze the macro and response when an exception occurs.
The set first exception option which selects whether to set the exception flag on the first response. Unlike the two other macro types, the “send Primitive” macro type is not implicitly enabled for execution. You must set Bit 0 to a value of 1 or use the ENABLE/DISABLE MACRO EXECUTION command before the macro will be scheduled for execution. The last option, Bit 4, causes the HIU to not check the first macro response received for an exception. When the macro response buffer is first allocated, its contents are undefined which will cause the first response received to set the exception flag. Setting Bit 4 will prevent this exception, or you can initialize the contents of the macro response buffer with the INITIALIZE MACRO RESPONSE BUFFER command. Example 2–3 shows examples of the bit coding for various combinations.

UNILINK HOST ADAPTER 2–40 USER MANUAL MSB LSB Byte ACTIONS (hex) 0 0 0 0 0 0 0 0 = 00 Non-repetitive, must be explicitly enabled, 1 1 0 0 0 0 0 0 = C0 Repetitive, auto enabled, will not freeze exception 0 1 1 1 0 0 0 0 = 70 Repetitive, must be explicitly enabled, will freeze exception data, will not check first response for an exception Example 2–3 Macro Options Byte — Bit Coding The minimum macro reissue delay time word or double byte specifies the number of milliseconds to delay before reissuing a repetitive macro. The delay time ranges from 0 to 30,000 milliseconds in 10 millisecond increments. This option only specifies the minimum time to delay the macro and should not be used for time dependent applications. Heavy network loading could cause the macro to be delayed longer than this minimum delay. You can redefine a macro, but it must be disabled first with the ENABLE/DISABLE MACRO command, which will clear the exception flag and discard any outstanding responses. 2.10.5 Checking The Macro Response and Macro Status The GATHER MACRO RESPONSE command collects one or more macro responses. You can choose to retrieve the entire macro response buffer data along with the Macro Response Status Word (MRSW) or just the MRSW. You can also choose to retrieve all the buffers specified or just those with their exception flags set. In addition to the command code, specify the Source Identification number, the response type, and the buffer number or numbers. The response type byte can be either code 00, 01, or 02. Code 00 instructs the UNILINK Host Adapter to return all of the buffer data including the MRSW. Code 01 will return all of the buffer data, but only for the requested buffers with their exception flags set. Code 02 will return only the MRSW, for the requested buffers that have their exception flags set. The macro response exception flag is reset each time that the buffer data is retrieved with response type codes 00 and 01; it is not reset with response code 02.

UNILINK HOST ADAPTER 2–41 USER MANUAL You can request more than one buffer at a time; however, be sure that the total combined length of each buffer response does not exceed the maximum message length, or the ERROR RESPONSE will be returned. The Primitive data must fit into one host response I-Frame. The secondary address, MRSW, Primitive data length, and the Primitive data will be returned for each buffer number requested that meets the response type condition. Specifying buffer number 00 is a special case that ignores the value in the response type byte. In this case, the HIU will return the buffer number and buffer data for the first buffer that has its exception flag set. This allows your host application program to receive any exceptions as they occur. Table 2–3 describes the meaning for the different values of the MRSW. If the macro terminated abnormally, the exception flag will be set and the Termination Code will reflect the error. The exception flag will also be set if the macro is explicitly disabled or the secondary device has been disconnected by a host computer. Refer to Chapter 6 for a more detailed explanation of each termination code. Table 2–3 MRSW Values MRSW Values (hex) Description This macro has not been executed since the last time it was enabled. The number of times a repetitive macro response has been updated. Termination Code – the macro is disabled due to either an error, an exception, or an explicit disable. 0000 0001 8000 to 7FFF to FFFF

UNILINK HOST ADAPTER 2–42 USER MANUAL 2.10.6 Enabling and Disabling Macros The ENABLE/DISABLE MACRO EXECUTION command explicitly enables and/or disables defined macros for execution. When this command is processed the exception flag will be cleared and the MRSW reset to 0000 hex if the macro is being enabled, or the MRSW set to the disabled Termination Code 8001 hex if the macro is being disabled. Macros will only be enabled when their associated secondary device is online, otherwise, the ERROR RESPONSE will be returned for that macro. The adapter will return the ENABLE/DISABLE MACRO EXECUTION command code, the Source Identification number, and a list containing a pair of bytes for each requested buffer number. The first byte in the pair is the requested buffer number and the second byte is the response code which indicates whether the requested action was successful. 2.10.7 Initializing the Macro Response Buffer There are two ways to insure that only a valid exception will set the exception flag. The first way was shown in the DEFINE MACRO command. By setting Bit 3 in the macro options byte, the first macro response will be received, but not compared to the contents in the macro response buffer. Thereafter, the new responses will be compared to that first response. The second way is to store a predefined value in the macro response buffer by using the INITIALIZE MACRO RESPONSE BUFFER command. A useful application is to define a macro that retrieves the status information from a secondary device and sets the exception whenever the response is not “OK”. The operating manual for the secondary device gives the exact Primitive response that should be returned for a status “OK”. Preload this value into the macro response buffer. Then, the exception flag will be set when the response is anything other than the “OK” status that was expected. The INITIALIZE MACRO RESPONSE BUFFER command byte string includes the Source Identification number, the buffer number, the Primitive response being preloaded, and an automatic enable byte. The macro must be disabled before sending this command. The automatic enable byte can then be used to enable the macro for execution after the response buffer is loaded without having to issue a separate ENABLE/DISABLE MACRO EXECUTION command.

UNILINK HOST ADAPTER 2–43 USER MANUAL 2.10.8 Checking Memory Usage There is a certain amount of housekeeping that your host application programs will need to do for the flexibility provided by macros. Your programs should apply the following rules.
Your programs must assign and keep track of the Source Identification numbers.
Your programs must ensure that no more than 32 Source Identification numbers are active at a time. This is easily accomplished by maintaining an internal table in your applications program. If you need to assign another Source Id number and have already assigned 32 Source Ids, you can deallocate one number and allocate another. However, remember that deallocating a Source Id clears all macro buffers associated with that Source Id, so you should retrieve any outstanding responses before deallocating.
Your programs must keep track of the buffer numbers and the associated Source Identification number. This can also be accomplished by maintaining an internal table in your applications program.
Your programs must ensure that no more than 254 macro buffers are allocated. The REPORT MEMORY USAGE command will help your programs track these items. When your program sends Command Code 18, the UNILINK Host Adapter will return the Command Code, the number of memory bytes available, the number of unallocated macro buffers, the number of unallocated Source Identification numbers, and a list of all Source Identification numbers currently active. 2.10.9 Linking Macros In addition to the basic operations with macros, you can also link two macros to form a “store and forward” link between two secondary devices as illustrated in Figure 2–19. Data types from one device will be retrieved from one secondary and then transferred to the other secondary without any further host intervention. The LINK MACRO command, code 1C, accepts a Source Id and two macro command buffer numbers. Both macros must have the same Source Id or an error will be returned. The first macro command buffer number represents the the trigger macro. When the trigger macro is enabled and completes processing, the second macro command buffer number or action macro will be executed.

UNILINK HOST ADAPTER 2–44 USER MANUAL UNILINK Host Adapter Macro Response Buffer #A Macro Response Buffer #B Secondary #1 Secondary #2 Data Packet Data Packet Figure 2–19 Link Macro Store and Forward Operation Both macros must be disabled before the LINK MACRO command will be accepted. The trigger macro must be a valid Primitive 20 or A0 to read data from the secondary device. The action macro must be a valid Primitive 30 or B0 to write the data read to the other secondary. All of the define macro options on each macro command buffer are valid until the link is established. When the link is established, the action macro will be considered non-repetitive. When the link is terminated the original conditions will be valid again. The adapter will check the validity of the host supplied Primitives before linking them. The Primitives must use the same TT type, but may use different starting addresses (AAAA field of the Primitive). You must insure that the number of TT types (NNNN field of Primitive) and the starting addresses are valid for both secondaries involved. Once the link is established, just enable the trigger macro to begin the process. The trigger macro behaves much like a non-linked macro, except that it is disabled while the action macro executes. Each time the trigger macro completes a read, the trigger macro is disabled, its data moved into the action macro buffer to create a valid write Primitive and the action macro is enabled. If the trigger macro receives an error from the secondary, the action macro is not enabled and the exception flag is set disabling the trigger macro.

UNILINK HOST ADAPTER 2–45 USER MANUAL Once the action macro has successfully completed, the trigger macro behaves as though the link never existed. If it is a repetitive macro, it will be enabled. The trigger macro’s exception flag is also set as though the link never existed except that it will not be set until the action macro has completed execution. The exception flag of the action macro is only set when an error occurs for its secondary device. If the action macro can not be executed for any reason, such as the secondary is offline, the link will be automatically terminated. The trigger macro will then execute as a non-linked macro. You will need to correct the problem, then execute a recovery subroutine that will perform the following steps. 1. Disable the trigger macro. 2. Reissue the LINK MACRO command. 3. Enable the trigger macro to start executing the link again. The link is not automatically terminated if the trigger macro fails. 2.10.10 Network Performance You can improve the performance of your networks by adjusting the bandwidth of the HIUs. The statistical commands will provide a picture of transaction bottlenecks that you can also adjust. One performance measure was already discussed in Paragraph 2.6.2. 2.10.10.1 Network Bandwidth The Network Manager serves as the primary in a TIWAY I network. It handles all communications between HIUs and other secondaries. It uses Network Manager buffers to temporarily store requests and responses before they are forwarded to the appropriate devices. These buffers are divided between the HIUs on the network. The number of buffers assigned to a particular HIU its bandwidth. The more buffers allocated to the HIU, the more requests the Network Manager function can simultaneously process for that HIU.

UNILINK HOST ADAPTER 2–46 USER MANUAL 2.10.10.2 NM Buffer Allocation These buffers are allocated implicitly with the background monitor function. However, the NM function in an adapter in the MHIU/EHA mode does not support background monitor or multiple hosts. The value specified for Option–09 of the CONFIGURE NETWORK MANAGER command will be allocated to each HIU function as the NM function brings it online. If no value was specified for Option–09, the value will default to one fourth of the available buffers. An amount other that the default number of buffers can be allocated explicitly with the ALLOCATE NETWORK MANAGER BUFFERS command when the number of buffers allocated by the background monitor is zero or if issued before the NM function is enabled by the CONFIGURE NETWORK MANAGER command. The ALLOCATE NETWORK MANAGER BUFFERS command can only be issued by the host computer attached to the adapter functioning the Network Manager and can only be issued once for each as HIU. After the buffers are allocated, they will remain allocated until the NM or MHIU is reset. The adapter will return the command code and the HIU address if the ALLOCATE NETWORK MANAGER BUFFERS command is accepted. Your applications software can issue the REPORT NETWORK MANAGER BUFFERS AVAILABLE command to determine how many buffers are unused. To use it, send the one byte command, code 35. The adapter will return the command code, the total number of NM buffers, and the number of NM buffers available.

UNILINK HOST ADAPTER 2–47 USER MANUAL 2.10.10.3 Adjusting An HIUs Bandwidth The REPORT NETWORK BANDWIDTH ALLOCATION command, code 36, returns counters that reflect the relative network activity for a specific HIU. The counters do not reset after reaching their maximum value and must be explicitly reset. Although the HIUs on the network have no direct control over the number of Network Manager buffers allocated to them, they can control how those buffers are used with the ALLOCATE HIU BANDWIDTH command. This command defines how the buffers are to be divided between direct requests/non-repetitive macros and repetitive macros by specifying how many of the allocated buffers will be used for repetitive macros. By default, repetitive macros can use all of the NM buffers allocated to the HIU. This command also limits the number of outstanding requests for a single secondary device, preventing one secondary from dominating the entire bandwidth. The default for this parameter is the smaller of two requests per secondary or the number of NM buffers allocated to the HIU. Both parameters are single bytes ranging from 00 to the number of NM buffers allocated to the HIU. The command code will be returned if the command is accepted. Your applications software may issue this command more than once in order to change the parameters to match the demands as they change. Issue the REPORT HIU BANDWIDTH ALLOCATION command to determine the buffer allocation and retrieve macro statistical counters. The statistical counter parameters are long words that must be explicitly reset when they reach their maximum values. The command string includes the command code and the optional reset counters code. There are two sets of counters, one for repetitive macros and the other for non-repetitive macros. The first counter in each set counts the number of I-Frame pairs sent and received by the macro type. The second counter in each set counts the number of I-Frame bytes sent by the macro type. The third counter in each set counts the number of I-Frame bytes received by the macro type. These counts do not include any HDLC overhead or communications counts between the NM and the HIU. Reset these counters by sending the command string 1A 01. The adapter will return the command code 1A if accepted.

UNILINK HOST ADAPTER 2–48 USER MANUAL 2.10.10.4 Performance Statistics The REPORT NETWORK MANAGER SECONDARY STATISTICS and REPORT NETWORK MANAGER NETWORK STATISTICS commands are provided as network diagnostic aids for locating bottlenecks or faulty secondaries. The REPORT NETWORK MANAGER SECONDARY STATISTICS command, code 37, returns statistics for a specific secondary device. These statistics are counters reflecting the communications between the Network Manager and the secondary. Each transaction will update the counters until their maximum value is reached. Then the command must be issued to reset the counters. You may want to reset the counters before beginning the diagnostic period so that the counts start at the zero baseline. The second command, REPORT NETWORK MANAGER NETWORK STATISTICS — code 38, returns statistical counters for an specific media channel. The counts reflect the activity between the Network Manager and all secondary addresses. Like the secondary statistics counters, these counters are not incremented after reaching their maximum value and must be reset explicitly with the special command sequence. The REPORT HIU STATUS command returns the connection status of the HIU and statistics on network performance. The statistics are counts for Network Manager to HIU communications. The counters are not updated after reaching their maximum value and must be explicitly reset.

3–1 USER MANUAL CHAPTER 3 CONFIGURING THE HOST COMPUTER PORT 3.1 THE HOST COMPUTER INTERFACE The UNILINK Host Adapter communicates with a wide range of host computer devices through a serial binary data interface using EIA RS–232–C control signals and EIA RS–423–A drivers as illustrated in Figure 3–1. This port is configurable for baud rates up to 38.4K bits per second; synchronous or asynchronous modem operation; full or half duplex; and even, odd, or no parity. A choice of two data link protocols are available; the Non–Intelligent Terminal Protocol (NITP) or BDLC, a byte-oriented subset of the ANSI X3.66 standard protocol. Host Computer UNILINK RS–232–C/RS–423–A Figure 3–1 Host Computer Interface

UNILINK HOST ADAPTER 3–2 USER MANUAL 3.2 RS–232–C/RS–423–A PHYSICAL INTERFACE Port 3 on the UNILINK Host Adapter, shown in Figure 3–2, is a serial communications interface which implements a subset of RS–232–C control, data, and timing signals using RS–423–A drivers and receivers. It is a 25-pin female “D” connector wired as Data Terminal Equipment (DTE) for connection to Data Communications Equipment (DCE). This connector uses the RS–232–C Type “D” pin assignments as listed in Table 3–1. Any pins not listed should remain vacant in order to prevent damage to the host computer or the UNILINK Host Adapter. A000654 Port 1 Port 2 Port 3 Port 4 AC NEUT AC LINE GND 1 2 3 4 5 I/O Host Communications Port Figure 3–2 Host Communications Port

UNILINK HOST ADAPTER 3–3 USER MANUAL Table 3–1 RS–232–C/RS–423–A “D” Connector Pin Assignment Interchange Circuit Connector Pin No. CCITT Description AA 1 101 Protective Ground Signal Ground Transmitted Data Recieve Data Request To Send Clear To Send Data Set Ready Data Terminal Ready Recieve Line SignalDetector Transmitter Signal Element Timing Reciever Signal Element Timing 102 103 104 105 106 107 108/2 109 114 115 7 2 3 4 5 6 20 8 15 17 AB BA BB CA CB CC CD CF DB DD Since the adapter will typically be operating in noisy industrial environments, it is recommended that the cable length not exceed 50 feet. 3.2.1 Connection to DCE Equipment Port 3 is configurable for synchronous or asynchronous modem operation, even, odd, or no parity, and baud rates up to 38.4K bits per second. These parameters are configured using the two dipswitch banks shown in Figure 3–3. The actual settings are described in more detail in Paragraph 3.3.1.1. LEDs Reset Number 2 Number 1 Figure 3–3 Dipswitch Locations

UNILINK HOST ADAPTER 3–4 USER MANUAL When the synchronous modem operation is selected, the adapter expects the modem to provide the clocking signals on pins 15 (DB) and 17 (DD). Selecting synchronous modem operation does not mean that you have selected a synchronous data link protocol such as the bisynchronous data link protocol. The adapter supports two asynchronous data link protocols which are described in further in Paragraph 3.3. 3.2.2 Connection to DTE Equipment You can also connect a host computer that has a DTE port, such as a microcomputer, to Port 3 for asynchronous communications by using a null modem cable. A null modem cable uses 25-pin type “D” connectors and RS–232–C cable wired as shown in Figure 3–4. Both the adapter and the attached host see that each is connected to a DCE device. The attaching cable should not exceed 50 feet in length. You may order this cable from your Siemens distributor (P/N;VPU–200–3605). 25 1 14 13 25 1 14 13 I00 Attached Device DTE GND TxD RxD RTS CTS DSR GND DCD GND TxD RxD RTS CTS DSR GND DCD DTR DTR UNILINK Host Adapter DTE RxCLK–No connection TxCLK–No connection Figure 3–4 Cable For Connecting To DTE Equipment (Null Modem)

UNILINK HOST ADAPTER 3–5 USER MANUAL The IBM PC/AT uses a 9-pin “D” connector for its serial interface port. A null modem cable diagram for the IBM PC/AT port is shown in Figure 3–5. 6 1 9 5 14 25 1 13 GND DTR SD RD DCD RI CTS RTS DSR TxD RxD RTS CTS DSR GND DCD IBM PC/AT 9–Pin UNILINK Host Adapter 25–Pin Figure 3–5 IBM PC/AT 9-Pin Null Modem Cable Diagram

UNILINK HOST ADAPTER 3–6 USER MANUAL 3.2.3 Multidrop Host Interface Circuit You can multidrop up to 32 adapters using modems in a multipoint circuit as shown in Figure 3–6. This allows the host computer to control multiple TIWAY I networks; however, each adapter must use the BDLC protocol. Each adapter must be assigned a unique address with dipswitches. The BDLC protocol uses the addresses to route messages to the correct network. A multipoint circuit represents the network layer of the Open Systems Interconnection model described further in Reference 4 in the Preface and in the TIWAY I Systems Manual (PPX:TIWAY–8101). Host Computer



 UNILINK Host Adapter UNILINK Host Adapter UNILINK Host Adapter TIWAY1 Network #1 TIWAY1 Network #2 TIWAY1 Network #3 4-wire leased line or equivalent wire Figure 3–6 Multidrop Host Interface Circuit NOTE You should select half-duplex operation for the modems when you multidrop to prevent the network modems from simultaneously raising the carrier.

UNILINK HOST ADAPTER 3–7 USER MANUAL 3.2.4 XON/XOFF Flow Control XON/XOFF flow control is provided at Port 3 to accommodate host computers with small input buffers. This is achieved with the XON and XOFF flow control characters sent from the host computer. Transmission will stop within four characters after XOFF is received from the host. For BDLC, the XON and XOFF characters must be sent as the 8-bit hexadecimal characters 11 and 13, respectively, with the eighth bit set to zero. For NITP, the XON and XOFF characters must be sent as 7-bit ASCII characters 11 and 13 with the parity matching the host computer parity. This flow control will operate with either the NITP or BDLC protocols, but the adapter must be set for Full Duplex communications by setting Position 3 of Dipswitch 2 up. The adapter will recover from host computer failures by resetting the flow control when the starting delimiter of the next frame is received. However, that frame will be discarded and must be retransmitted by the host computer. If you are using a Network Interface Unit (NIU); i.e., Ethernet, Sytek, etc., or a host device that implements XON/XOFF flow control with the BDLC protocol, the BDLC data values 11 and 13 hex may inadvertently trigger the flow control. If possible, you should deselect the XON/XOFF flow control on the NIU or host device, or select the NITP protocol on the adapter. Flow control is only provided as a convenience for the host devices; the adapter will not try to stop a host transmission with XOFF.

UNILINK HOST ADAPTER 3–8 USER MANUAL 3.3 HOST PORT COMMUNICATIONS The UNILINK Host Adapter provides a choice of two data link layer protocols for ensuring data integrity through the physical link; the Byte–oriented Data Link Control (BDLC) protocol and the Non–Intelligent Terminal Protocol (NITP). Both protocols include link establishment, message framing, and error checking functions. In addition, the BDLC protocol provides for link disconnection and sequence control. The protocol and other host port parameters are selected with dipswitches. Several factors are important in deciding which protocol to use. 3.3.1 Choosing a Host Protocol The NITP protocol was designed to be simple and still provide data integrity. The major features of NITP are listed below.
It works in a point-to-point circuit, connecting the host computer to the adapter. NITP cannot be used in a multipoint circuit because it does not have the ability to address individual adapters.
Messages are transmitted in a frame that includes beginning and ending delimiters, message character count, and a checksum. : Character Count Message Body ECC ; Figure 3–7 NITP Message Structure

UNILINK HOST ADAPTER 3–9 USER MANUAL
The host computer must wait for the adapter response for the command issued, before another command can be issued. This command/response sequence, illustrated in Figure 3–8, ensures that the response matches the command.
It is designed to work with a wide range of ASCII host devices, from ASCII terminals to intelligent workstations.
It supports a subset of the ASCII character set, “:”, “;”, “0–9”, and “A–F”. The adapter will ignore all other ASCII characters between the ending semicolon delimiter and the next beginning colon delimiter, so the host computer can use these characters for routing control.
It is easier to implement than the BDLC protocol, but it is also much slower since the data is transmitted as ASCII characters requiring two bytes for each data value. For example, the hexadecimal value: 0E hex

/ \ becomes 30 45 (ASCII characters “0” and “E”) More detailed specifications are given in Appendix A.   
         Figure 3–8 NITP Command/Response Sequence

UNILINK HOST ADAPTER 3–10 USER MANUAL The BDLC protocol is a byte–oriented subset of the ANSI X3.66 standard protocol, similar to the ISO standard HDLC protocol. The major features of the BDLC protocol are listed below.
It provides a higher level of data integrity and throughput improvements over NITP, but it is also more complex to implement.
It uses send and receive counts in a control field for improved data integrity.
Throughput is improved by transmitting the data as eight-bit binary values or hexadecimal, making this protocol approximately twice as fast as NITP. However, you will have to write and/or install the BDLC protocol driver software on your host computer.
Additional throughput improvements are gained by using the multiple outstanding transaction capability, illustrated in Figure 3–9. This allows the host computer applications software to continue issuing commands before the network response is returned. The host computer can issue a network request to secondary device #1, then another to secondary device #2, followed by the command to retrieve the response from secondary device #1.
It uses an address to distinguish individual adapters in a multipoint host interface circuit as described in Paragraph 3.2.3. More detailed specifications are given in Appendix B.

UNILINK HOST ADAPTER 3–11 USER MANUAL BDLC Host Command BDLC Host Command RR, “Poll” RR, “Poll” RR, “Message Received” RR, “Message Received” First Network Response Second Network Response Host Computer UNILINK Host Adapter Figure 3–9 BDLC Multiple Outstanding Transactions Another consideration is that of the six configurable modes described in Chapter 2, two of those modes emulate the original TIWAY I Host Adapter, meaning that they require the NITP protocol. If you plan to use either the Master Host Interface Unit (MHIU) or Host Interface Unit (HIU) in EHA mode, you must also use the NITP protocol because these modes do not support commands for configuring network parameters and the dipswitch used to define the BDLC address is used to define those network parameters. Another factor to consider is the type of secondary devices that will be on your network. If you will be connecting Computer Interface Modules (CIM) or Intelligent Tank Transmitters (ITT) in CIM mode, you must configure the adapter as an MHIU/EHA which requires the NITP protocol. ITTs may also be used in the TIWAY mode without the above restriction.

UNILINK HOST ADAPTER 3–12 USER MANUAL          The host port communication parameters are configured with two 10-position dipswitches located at the front of the adapter as shown in Figure 3–3. To select NITP as the operating protocol, set position 1 of Dipswitch 1 up as shown in Figure 3–10.
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  UP DOWN $ Figure 3–10 NITP Dipswitch Settings NOTE The host port parameters specify the physical layer protocol parameters and do not imply that the data link protocols can be either asynchronous or synchronous. Both the BDLC and NITP protocols are asynchronous data link layer protocols.

UNILINK HOST ADAPTER 3–13 USER MANUAL Next set the positions on Dipswitch 2 to correspond with the communication parameters set for the host computer. The adapter always communicates with the host computer using seven data bits, one start bit, and one stop bit. The baud rate settings for Positions 5–8 of Dipswitch 2 are shown in Table 3–2. Position 1 of Dipswitch 2 enables or disables parity bit generation and checking. Position 2 of Dipswitch 2 selects even or odd parity when parity generation and checking is enabled. Position 3 of Dipswitch 2 selects full duplex or half duplex operation. Position 4 of Dipswitch 2 selects synchronous or asynchronous modem communications. Selecting synchronous only enables the adapter to use the TxCLK (DD) and RxCLK (DB) RS–232–C control signals. The adapter will not process synchronous control characters from synchronous data link protocols such as BiSync. Table 3–2 Host Port Baud Rates Dipswitch 2 Switches Baud Rate 0 0 0 0 1 1 1 1 1 1 1 0 0 5 6 7 8 MSB LSB 1 1 1 0 0 0 0 1 1 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 1 0 1 110 150 300 600 1200 2400 4800 9600 19200 38400 0 = Down 1 = Up

UNILINK HOST ADAPTER 3–14 USER MANUAL Position 9 on Dipswitch 2 is for selecting the adapter’s operational mode and will be discussed in more detail in Chapter 2. Position 10 should be down for normal operation. The other switch positions on Dipswitch 1 define the TIWAY I network parameters and are discussed in more detail in Chapter 4. To select the BDLC protocol as the operating protocol, set position 1 of Dipswitch 1 down as shown in Figure 3–11. With BDLC, the host port parameters are configured with both dipswitches. Since the data is transferred as 8-bit bytes, there is no parity bit selection.
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 ! UP DOWN $ Figure 3–11 BDLC Protocol Dipswitch Settings

UNILINK HOST ADAPTER 3–15 USER MANUAL Table 3–3 BDLC Protocol Address Dipswitch 1 Positions Address 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 0 0 0 0 0 4 5 6 7 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 = Down 1 = Up Set the adapter’s BDLC protocol address using Table 3–3 as a guide and set the positions on Dipswitch 2 to correspond with the communication parameters of the host computer. The baud rate settings are shown in Table 3–2. Position 9 of Dipswitch 2 defines the adapter’s operational mode (discussed further in Chapter 2). Position 10 should be down for normal operation. Positions 9–10 of Dipswitch 1 define the Host Command timeout value discussed in Paragraph 3.4.

UNILINK HOST ADAPTER 3–16 USER MANUAL 3.4 HOST COMMAND TIMEOUT The Host Command Timeout is the user-selectable time period that guarantees a response from the adapter will be returned within that limit. If the adapter has not received a response from the secondary device before this time period expires, the adapter will return the ERROR RESPONSE to the host computer. This time-out function operates with either host communication protocol for the time-out values shown in Table 3–4. Note that a timeout value of 0 seconds signifies that the adapter will not accept any host commands since the timeout occurs immediately. When the Host Command Timeout is set to 0, the adapter is configured in the Standalone Network Manager (SANM) mode. NOTE The adapter must be reset before any dipswitch changes are recognized. Table 3–4 Host Command Timeout Dipswitch Settings Position 9 Down Down Up Up 10 Down Up Down Up Description 0 sec 10 sec Timeout 20 sec Timeout 40 sec Timeout – Accepts No Host Commands (SANM Mode) DIPSWITCH 1

4–1 USER MANUAL CHAPTER 4 THE TIWAY I NETWORK PORTS 4.1 NETWORK PORTS The UNILINK Adapter offers a choice of two physical interfaces for network communications; the Local Line or Modem interfaces. The following table lists the model numbers and the type of interfaces in each. Table 4–1 UNILINK Adapter Models Model Number PPX:500–7111 Network Port Dual Local Line Dual RS–232–C/423 Dual Local Line Dual RS–232–C/423 Supply Voltage 120 VAC 120 VAC 240 VAC 240 VAC PPX:500–7112 PPX:500–7113 PPX:500–7114 More information on the media types can be found in the TIWAY I Systems Manual (PPX:TIWAY–8101) and in the UNILINK Adapter Installation and Operation Manual (PPX:TIWAY–8106).



  
  4.1.1 Local Line Interface Port 1 Port 2 Port 3 Port 4 Local Line Interface Ports I/O 12345 Figure 4–1 Local Line Interface Ports The Local Line interface to TIWAY I is a female 9-pin “D” connector shown as Ports 1 and 2 in Figure 4–1. Port 1 is the primary network port. Port 2 provides support for redundant media transmission when Ports 1 and 2 are connected to a redundant twisted pair cable network (discussed further in Paragraph 4.2 ). The pin assignments for these ports are given in Table 4–2. Table 4–2 Local Line Connector Pin Assignments Pin 1 2 3 4 5 6 7 8 9 Name Sheild LLM+ LLM– Description Reserved Reserved Cable shield and signal common Reserved Reserved Positive biased signal line Reserved Reserved Negative biased signal line

UNILINK HOST ADAPTER 4–3 USER MANUAL The TIWAY I Local Line interface has the advantage of being more economical than the modem interface since the media is shielded twisted pair cable, such as Belden 9860 or Belden 9271. Figure 4–2 shows the TIWAY I bus structure with the network trunkline cable, which can generally extend up to 25,000 feet with droplines up to 100 feet in length. Figure 4–3 is a chart showing the maximum cable distances compared to the number of stations on the TIWAY I network. NOTE PM550 CIM users should refer to Appendix C for different media length factors. Host Computer UNILINK TIWAY I UniLink Host Adapter ( MHU) RS–232–C/RS–423–A Host Interface Cable Figure 4–2 TIWAY I Bus Structure

 
 
  
 30 25 20 15 10 8 5 4 3 2 1 6 7 10 50 100 250 Cable Unit Loading (Number of Stations) 19.2 k bps 38.4 k bps 57.6 k bps 115.2 k bps 115.2 k bps or lower Belden 9860 Belden 9271 Cable Distance (1000’s of feet) 20 5 I003648 Figure 4–3 Number of Local Line Secondaries vs. Cable Distance Signals are coupled between the transmission line and the transmit/receive circuits to provide a level of rejection to normal AC power frequency interference and other noise sources. Information is transferred on the TIWAY I twisted pair media asynchronously at user selectable data rates of 110, 150, 300, 600, 1200, 2400, 4800, 9600, 19.2K, 38.4K, 57.6K, and 115.2K bits per second, in half-duplex mode and NRZI encoding. The Local Line interface does not support synchronous operation or NRZ.

UNILINK HOST ADAPTER 4–5 USER MANUAL 4.1.2 Modem Interface A000654 Port 1 Port 2 Port 3 Port 4 AC NEUT AC LINE GND 1 2 3 4 5 I/O Interface Ports Figure 4–4 RS–232–C/RS–423–A Modem Interface Ports The modem interface is a standard “Type E” DTE configuration as defined in the EIA RS–232–C standard that uses EIA RS–423–A drivers. This interface uses a female 25-pin “D” type connector on both Ports 1 and 2 as shown in Figure 4–4. These two ports support redundant media transmission when connected to redundant modem networks. The pin assignments shown in Table 4–3 are supported. All other pins should be left vacant to prevent damage which may be caused by non-standard pin usage.



  
  Table 4–3 RS–232–C/RS–423–A “D” Connector Pin Assignment Interchange Circuit Connector Pin No. CCITT Description AA 1 101 Protective Ground Signal Ground Transmitted Data Receive Data Request To Send Clear To Send Data Set Ready Data Terminal Ready Recieve Line Signal Detector Transmitter Signal Element Timing Reciever Signal Element Timing 102 103 104 105 106 107 108/2 109 114 115 7 2 3 4 5 6 20 8 15 17 AB BA BB CA CB CC CD CF DB DD The line drivers and receivers meet the requirements for the RS–423–A and RS–232–C standards. The modem interface is user–selected for either asynchronous or synchronous operation at data rates of 110, 150, 300, 600, 1200, 2400, 4800, 9600, 19.2K, 38.4K, 57.6K, and 115.2K bits per second. Modem interface circuits can be longer than the 25,000 feet limit of the Local Line interface. This interface must be used for cross-building or cross-town circuits. The modems used must be non-intelligent and have data transparency. Non-intelligent refers to the class of modems that do not have an internal command set. Modems such as the Hayes Smartmodem and compatibles do have an internal command set and should not be used. Generally, modems that meet the Bell 103, 202, and 208 specifications will work, but the Bell 212A class modems will not. In addition to being non-intelligent, the modems must support data transparency which means no start bits, no stop bits, and no parity. This is necessary because TIWAY I uses the bit-oriented HDLC protocol to transfer information between devices. Most short haul modems are non–intelligent and provide data transparency.

UNILINK HOST ADAPTER 4–7 USER MANUAL You also have a choice of using either NRZ or NRZI encoding with the modem interface. NRZI is recommended because of its self-clocking properties. A special Clear-to-send (CTS) to transmit timing delay has been provided for use with radio link modems, ranging from 0 ms to 1,000 ms in 10 ms increments. There is also an RTS/CTS timeout. These delay values are set through configuration commands described in Chapter 2 and Chapter 5. 4.1.3 Runaway Transmitter Recovery The UNILINK Host Adapter is equipped with a timeout or runaway transmitter recovery mechanism which ensures that the transmitter does not remain turned on longer than twice the time required to send the maximum length message. If the transmission exceeds this limit, the adapter will perform a hardware reset, discarding all macro buffers and any outstanding directives. NOTE The hardware reset restores the adapter to the initialized or power-up state. At this point, the adapter will have to be reconfigured and the network restored to its operating state.



  
  4.2 REDUNDANT MEDIA TRANSMISSION Most TIWAY I conformant devices support a redundant media scheme which provides active access to a device over one of two independent media channels. Should access to a device fail on one channel, communications can be automatically or manually switched to the alternate channel. This type of a circuit is illustrated in Figure 4–5. Examples of the software commands are given in Chapter 2. UNILINK Drop Cables Up to 254 Secondaries Secondary Bus (alternate trunk) Bus (main trunk) Figure 4–5 Redundant Media Circuit NOTE Redundant media is provided to improve a network’s mission reliability. However, the adapter cannot use the dual media ports to access two independent networks.

UNILINK HOST ADAPTER 4–9 USER MANUAL 4.3 TIWAY I HDLC NETWORK PROTOCOL The TIWAY I network uses the HDLC protocol in the unbalanced, normal response mode (UNRM) for transmission of commands and responses. In this mode a single Network Manager (primary) controls the flow of messages between secondary devices. Information flows between the primary and secondaries inside HDLC I-Frames or information frames. The destination of the frame is specified by the address field, the nature of the frame by the control field, and any data specified by the information field. The TIWAY I primitive requests and responses are encapsulated inside HDLC I-Frames according to the format shown in Figure 4–6. Flag Address Control Information FCS Flag Figure 4–6 HDLC Frame

 

  
 4.4 SETTING THE NETWORK PORTS PARAMETERS The network ports must be explicitly enabled with the CONFIGURE HIU and CONFIGURE NETWORK MANAGER commands. The syntax for these commands is given in Chapter 5. The network parameters specified explicitly in these commands overrides the default values set by the dipswitches. The choice of the host port protocol also determines whether network port parameters can be defined on the dipswitches or through internal constants. The BDLC protocol uses both dipswitches to define the host port parameters and will use these internal constants for network defaults:
Local Line media —  115.2K baud,  half duplex,  asynchronous, and  NRZI
RS–232–C/RS–423–A media —  9600 baud,  full duplex,  synchronous, and  NRZ The NITP protocol uses the values defined on Dipswitch 1 as the defaults as shown in Figure 4–7. The network parameters are then set with Positions 2–8 of Dipswitch 1 as illustrated in Figure 4–7. The applicable baud rate settings are given in Table 4–4. These settings should match the settings for any other TIWAY I network devices.

UNILINK HOST ADAPTER 4–11 USER MANUAL         
 
  

 
    







  


  








 


 
 







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  Figure 4–7 Network Port Dipswitch Settings NOTE The Local Line interface will always be asynchronous, half duplex, and use NRZI encoding regardless of the setting of these dipswitches. Table 4–4 Network Port Baud Rates Network 0 0 0 0 1 1 1 1 1 1 1 0 0 5 6 7 8 MSB LSB 1 1 1 0 0 0 0 1 1 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 1 0 1 110 150 300 600 1200 2400 4800 9600 19200 38400 Baud Rate 1 1 1 1 1 1 0 1 57600 115200 0 1 = Down = Up

5–1 USER MANUAL CHAPTER 5 HOST COMMAND SET REFERENCE 5.1 INTRODUCTION This chapter presents the syntax for each command. The command syntax descriptions begin in Paragraph 5.2 and are listed in numerical order (starting at 00 to FE hexadecimal). The command syntax conventions are defined in Paragraph 5.1.1. Certain network address values have special meanings and are described in Paragraph 5.1.3. Paragraph 5.8 provides a summary of the command syntax including both the command and response syntax. Paragraph 5.9 provides a list of the command codes and descriptions, listed in numerical order and Paragraph 5.10 provides a similar list that groups the commands according to their use. 5.1.1 Command Syntax Conventions Command Code Parameter #1 Parameter #2 Parameter #n Figure 5–1 Command String Structure Command strings contain the one-byte command code and may include one or more parameters as defined by each command’s syntax. All values in the command string are in hexadecimal notation. The selected host interface protocol, discussed in Chapter 3, will determine whether the command string is transferred in binary format or converted to ASCII characters. The following conventions are used to define the command syntax used in the succeeding sections:
The most significant bit, labeled Bit 0, is the left most bit in the byte, word, or long word.
All command code numbers are one byte, hexadecimal values and will always be the first byte in the command string.
Each letter in a command parameter indicates a nibble (four bits) so that a:  byte is represented as aa  word is represented as aaaa  and a long word is represented as aaaaaaaa
Parameters containing more than eight nibbles (long word) are represented as aaaa...

UNILINK HOST ADAPTER 5–2 USER MANUAL
All codes and parameters are separated by spaces.
Optional parameters are surrounded by parentheses, like (aa bb).
Parameter sequences that may be repeated are surrounded by brackets, like [aa bb].
Certain letters designate a specific parameter type used throughout the command syntax descriptions for easier identification. These are:  aa — the secondary device address.  ss — the Source Identification number.  rr — the reset counters code.  oo — the option code. Commands may have one or more option codes.  pppp... — a TIWAY I Primitive.

UNILINK HOST ADAPTER 5–3 USER MANUAL 5.1.2 Usage Description A usage description is included with each command reference to give an indication of when the command should be used. The meaning of the usage descriptors are CONFIGURATION This command is used to configure the adapter for operation. This command can only be issued once to each adapter after they have been reset or powered up. INITIATION This command is used to initialize the network devices. OPERATION This command is used for ongoing communications between the host computer and the network devices. PERFORMANCE This command is used to gather statistical performance or status information on the adapter and the network devices, and to redefine certain operating parameters to improve network performance. TERMINATION This command is used to shut down or terminate network devices.

UNILINK HOST ADAPTER 5–4 USER MANUAL The cycle at power-up or reset is shown in Figure 5–2. Configuration Initiation Operation Performance Termination Figure 5–2 Command Usage Cycle 5.1.3 Secondary Addresses Secondary addresses are one byte in length and range from 1 to 254. The addresses 0 and 255 are reserved for special functions as indicated in Table 5–1. Normally the address 255 is used as a shorthand method to indicate that the command should be processed for all secondary devices on the network. Care must be used with this shorthand method because a host command timeout may occur before the response has been gathered from all of the secondaries. Your network will operate more efficiently if you number your secondary devices and HIUs beginning with address “1” and consecutively numbering the remaining devices.

UNILINK HOST ADAPTER 5–5 USER MANUAL Table 5–1 Secondary Addresses Decimal Address 0 1–254 255 Hexadecimal Address 00 01–FE FF Usage Reserved for special functions, refer to individual commands. Available for secondary device addresses. Reserved for special functions, normally used to indicate all secondary devices are to be effected by the command. 5.1.4 Active Command Codes In Each Mode Figure 5–3 is a decision tree illustrating the command codes that are active in each configurable mode. In addition to mode, the command tree asks whether the major components have been configured with their associated configuration commands. Power up YES YES YES YES YES NO NO NO NO NO MHIU EHA HIU EHA NM MHIU HIU YES NO YES NO YES NO YES NO YES NO 1–8, 21, FC–FF 1–8, 20–21. FC–FF 1, 2, 4–8, 21,FC–FF 20, 21,FC–FF 21, 31–38, FC–FF 21, 30–32, 34–38, FC–FF 20, 21 FC–FF 1–2, 4–10, 12–1C, 21, 30–32, 31–38, FC–FF 6–8, 10–1C, 21, 30–32, 34–38, FC–FF 6–8, 10–1C, 21, 31–38, FC–FF 6–8, 10–1C, 21, 30–32, 34–38, FC–FF 1–2, 4–10, 12–1C, 21, FC–FF 6–8, 10–1C, 21, FC–FF 20, 21, FC–FF Intended Mode Adapter Configured (Command 20) HIU Configured (Command 11) and Initialized by Network Manager Active Command Codes Network Manager Configured (Command 30) Figure 5–3 Active Command Tree

UNILINK HOST ADAPTER 5–6 USER MANUAL 5.2 ERROR RESPONSE An ERROR RESPONSE, rather than the normal command response, will be returned when the host request is invalid. Response: 00 dddd (aa) Parameters: dddd Error codes. All error codes and corrective actions are given in Chapter 6. aa The secondary address associated with the error code. This parameter is only included if applicable.

UNILINK HOST ADAPTER 5–7 USER MANUAL 5.3 BASE HIU COMMANDS The Base HIU commands are backward compatible with the original commands for the TIWAY I Host Adapter. These commands cause a direct network request to be issued to connect and disconnect secondaries, send data to and from secondaries, and read secondary statistics. Your applications software must wait for a response to be returned before issuing another command if you are using the NITP protocol. If you are using the BDLC protocol, you can have up to two outstanding transactions before the adapter will return the Receiver Not Ready (RNR) BDLC control frame. These commands are listed below.
Send Network Data — 01
Broadcast Network Data — 02
Poll Secondary — 03 (Available only in MHIU/EHA mode)
Connect Secondaries — 04
Disconnect Secondaries — 05
Read Secondary Log — 06
Read Secondary Diagnostics — 07
Read Adapter Diagnostics — 08 These commands will not be accepted by either the hosted or the stand-alone Network Manager modes.

UNILINK HOST ADAPTER 5–8 USER MANUAL 5.3.1 Send Network Data — 01 The SEND NETWORK DATA command sends a specified host Primitive to a network secondary via the Network Manager. Once the Primitive has been received by the secondary, the Network Manager polls the secondary for the Primitive response and returns it to the issuing HIU. The HIU then forwards the Primitive response to the attached host computer. Command: 01 aa pppp... Response: 01 aa pppp... Usage: OPERATION Modes: MHIU/EHA, HIU/EHA, MHIU, HIU Parameters: aa The secondary address to receive the Primitive data. pppp The TIWAY I Primitive data (command or response). This parameter begins with the length field of the Primitive.

UNILINK HOST ADAPTER 5–9 USER MANUAL 5.3.2 Broadcast Network Data Transfer — 02 The BROADCAST NETWORK DATA TRANSFER command sends the Primitive data to all online secondary devices. The secondary device log contains only those secondary devices in the network that are online. However, this type of information transfer does not use the full TIWAY I HDLC integrity checks to ensure message delivery. If the adapter is configured as an MHIU in EHA mode, the host applications software must issue a POLL command for each secondary device to collect the responses or some responses may be lost. In any other configuration, you should include a data element that is set in the secondary with the broadcast and checked by the host applications software by sending a SEND NETWORK DATA command to determine if the broadcast message was received. The data element can also be checked by the secondary devices program to cause it to perform a programmed process. This function can be more efficiently handled in non-MHIU/EHA networks by using macros for data acquisition. NOTE Before the data is broadcast, all pending TIWAY I I–Frames from all HIUs will be processed. Then no further directives will be processed until the broadcast completes. This could have a serious impact on the response time for normal network operations and should be used carefully. The following are typical uses for this command.
Time synchronization for all secondary devices. This could be used to signal all secondaries to reset their counters at the beginning of a production period.
Data collection via a snapshot read. The broadcast could signal the secondaries to move data to a designated area in the secondary device which will be retrieved later with a POLL or SEND NETWORK DATA command.

UNILINK HOST ADAPTER 5–10 USER MANUAL CAUTION You should not issue the BROADCAST NETWORK DATA TRANSFER command if your network contains Intelligent Tank Transmitters (ITTs) as secondary devices, or you could lose responses. Also, sending a BROADCAST NETWORK DATA TRANSFER command when your adapter is configured as either an MHIU or an HIU will cause a network HDLC error to be logged even though the information was received. This error will be included in the statistics from the READ SECONDARY DIAGNOSTICS, REPORT HIU STATUS, REPORT NETWORK MANAGER SECONDARY STATISTICS and the REPORT NETWORK MANAGER NETWORK STATISTICS commands. Command: 02 pppp... Response: 02 Usage: OPERATION Modes: MHIU/EHA, HIU/EHA, MHIU, HIU Parameters: pppp The TIWAY I Primitive request. This parameter begins with the length field of the Primitive.

UNILINK HOST ADAPTER 5–11 USER MANUAL 5.3.3 Poll Secondary — 03 The POLL SECONDARY command is issued to collect the responses to the broadcast command or a SEND NETWORK DATA command that timed out in the Network Manager (NM). This command is only valid for an adapter configured as an MHIU in EHA mode. Command: 03 aa Response: 03 aa pppp... Usage: OPERATION Modes: MHIU/EHA Parameters: aa The secondary address being polled. pppp The TIWAY I Primitive data response. This parameter begins with the length field of the Primitive.

UNILINK HOST ADAPTER 5–12 USER MANUAL 5.3.4 Connect Secondaries — 04 The CONNECT SECONDARIES command logically connects one or more secondaries to the network. Each host computer must issue this command for the secondary devices that it will be communicating with. Trying to connect many secondary devices at the same time could cause the host command time-out to expire if the secondary devices do not respond in that time limit. If this occurs, the error response will be returned and the host computer will have to retrieve the secondary log to determine which secondary devices were connected. Command: 04 [aa] Response: 04 [bb] Usage: INITIATION Modes: MHIU/EHA, HIU/EHA, MHIU, HIU Parameters: aa The secondary addresses to be connected. Specifying address FF will attempt to connect all secondaries. bb The secondary addresses that connected properly. If bb is 00 hex, none of the secondaries addressed were connected.

UNILINK HOST ADAPTER 5–13 USER MANUAL 5.3.5 Disconnect Secondaries — 05 The DISCONNECT SECONDARIES command removes the specified secondaries from the secondary log and automatically disables associated macros, setting their MRSWs to the appropriate Termination Code. If the HIU processing this command was given permission to issue a DISC on the network when it was initialized, then this command also issues a DISC directive that logically disconnects (possibly causing the secondary device to perform a hardware reset) the specified secondary from the network. This does not prevent another HIU or the background monitor from reconnecting the secondary. Once a secondary device is logically disconnected, it will appear offline to all HIUs on the network, causing the remaining network HIUs to set the exception flag and MRSWs for any macros associated with that secondary. Trying to disconnect many secondary devices at the same time, using the global address FF hex, could cause the host command timeout to expire if the secondary devices cannot respond in that time limit. If this occurs, the ERROR RESPONSE will be returned and your applications software should retrieve the secondary log to determine which secondary devices were disconnected. Command: 05 [aa] Response: 05 [bb] Usage: TERMINATION Modes: MHIU/EHA, HIU/EHA, MHIU, HIU Parameters: aa The secondary addresses to be disconnected. Specifying address FF will attempt to disconnect all secondary devices listed in the secondary log. bb The secondary addresses that disconnected properly. If bb is 00 hex, none of the secondaries addressed were disconnected.

UNILINK HOST ADAPTER 5–14 USER MANUAL 5.3.6 Read Secondary Log — 06 The READ SECONDARY LOG command returns the list of secondaries that are logically connected to the HIU. Command: 06 Response: 06 [aa] Usage: OPERATION Modes: MHIU/EHA, HIU/EHA, MHIU, HIU Parameters: aa The secondary addresses currently connected to the HIU. If no secondaries are connected, the value returned will be 00.

UNILINK HOST ADAPTER 5–15 USER MANUAL 5.3.7 Read Secondary Diagnostics — 07 The READ SECONDARY DIAGNOSTICS command returns statistics for the specified secondary device. Only counts related to the issuing HIU are returned. With the exception of the number of I–Frames transmitted to and from the secondary, these counters do not represent an exact count of events and are intended only to show trends that may indicate problems. The counters will not be updated for offline secondaries or after reaching their maximum value of FFFF. The host computer must explicitly reset the counters by issuing this command with the reset counter code. Command: 07 aa (rr) Response: 07 aa (bbbb cccc dddd eeee ffff gggg hhhh iiii) Usage: PERFORMANCE Modes: MHIU/EHA, HIU/EHA, MHIU, HIU Parameters: aa The secondary address. If the special address FF is used and the reset code parameter is set to 01, the statistics counters for all secondaries will be reset. The special address cannot be used to return the statistics counters for all secondaries simultaneously. rr The reset statistics counters code. This optional parameter was added to the original TIWAY I Host Adapter command to allow the counters to be reset. 00 = Return the statistics counters for the specified secondary, but do not reset the counters. 01 = Reset the statistics counters for the specified secondary and do not return any counts. Only the address field is returned with the command code when this option is selected. bbbb The number of polls successfully transmitted to the secondary. cccc The number of TIWAY I HDLC I–Frames successfully transmitted to the secondary. dddd The number of network errors including CRC errors, timeouts, aborts, and the loss of RS–232–C/RS–423–A control signals. eeee The number of TIWAY I HDLC I–Frames received. ffff This value will always be zero. gggg The number of TIWAY I HDLC errors, including command rejects (FRMR), invalid HDLC responses, and sequence errors. This number may reflect errors logged because a BROADCAST NETWORK DATA TRANSFER command was issued in a network that contains Intelligent Tank Transmitters (ITTs) as secondary devices. These errors are logged because the ITT returned a REJ even though the information was received.