QTech Q71B Quick Start Manual

www.qtech.co.nz Tel: 03 3663713 Overview The Q71B modem allows you to connect a DATRAN RTU via an RS232 serial port to a DATRAN 1200bps radio communications system using the V.23 FSK protocol but without the backward channel. This allows 1200bps in both directions as the modem is uses a special turn around feature. The Q71B interfaces to either a Tait TM81xx radio (fitted with a Q82 interface), or a DATRAN Q80 telemetry radio. The radio type needs to be specified so QTech can supply the correct cable. Each Q71B is supplied complete with a 1m Radio cable and a 400mm RS232 serial cable. The Q71B can also simplify radio network upgrades from 300bps to 1200bps as it removes the need to change the internal modem hardware. Prerequisites The DATRAN II eXcel must have Q03 firmware v5.21 or later. The Q90 software required is v3.27 or later. If using the DATRAN XL4 RTU, all versions are compatible. All versions of Workbench software are compatible.

www.qtech.co.nz Tel: 03 3663713 Power Supply Connections The Q71B is designed to operate from a supply voltage in the range 8.0V DC to 15.0V DC. A supply voltage greater than 15.0V will blow the 500mA fuse inside the Q71B. A supply voltage less than 8.0V will result in degraded or unreliable performance. The DATRAN XL4 RTU and the eXcel (Rev D) RTU have two RS232 ports; both can use the Q71B for analogue radio communications. The significant difference between the two ports, is that the lower RS232 port (RS232-B) on the Q22D has a +Vsup DC output supply line. The Q71B can be powered via this line, so long as jumper J23 on the Q22D is in the 1-2 position. RS232-A port on the processor does not have this supply line, so the Q71B must be powered through the three terminal power supply connector, the power supply connections are shown on the top cover Left Pin Middle Pin Right Pin G Power Supply Negative + Power Supply Positive (8V – 15VDC) Not connected The default installation position of the Q71B is on the lower RS232 port. All new RTUs will be configured with the correct jumper setting for this. However, please check this jumper on existing RTUs before using a Q71B. If using the modem on the RS232-A port do not apply power from both the port and the external supply If the DATRAN RTU is powered from a 24V DC system: Do not connect the Q71Modem to this 24V DC supply. Do not connect the Q71 modem to the RS232A port; use the 12V DC supply that the radio uses & connect to the Q71 power connector.

www.qtech.co.nz Tel: 03 3663713 Configuration The DATRAN II eXcel must be configured so that it will use the Q71B for communications. Power up the RTU and connect Q90 software to the RTU. Navigate to the “Communications” tab and set “Device Type” as shown below. The upper RS232 port is configured in the same way. Q03 RTU Configuration XL4 RTU Configuration Diagnostics The Q71B has three status LEDs. PWR – Power. Green LED is on when power is applied. RX – Receive. Orange LED in on when radio mute is active. TX – Transmit. Orange LED is on when RTU is transmitting. If the Green PWR LED is not on check the fuse. Tuning Q03 RTU Tuning Once the Q03D has been configured to use the Q71B, the transmit audio signal level can be adjusted by pressing the “Set TX Level” button in Q90. This will make the Q71B transmit a continuous tone, and an AC voltage meter can be placed across the pins of the connector labelled “LVL” in the Q71B. Turn the potentiometer anti-clockwise to reduce the signal level Turn the potentiometer clockwise to increase the signal level Note – this process will have already been performed as part of the factory setup at QTech prior to delivery. The default level is -3 dBm (548mV) into a 600 Ω resistive load. XL4 RTU Tuning This is performed in a very similar method to the above Q03 process but via Workbench.