Measurement Computing USB-1808-OEM Operation & User’s Manual

User's Guide May 2019. Rev 4 © Measurement Computing Corporation ...

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Preface About this User's Guide ....................................................................................................................... 5 What you will learn from this user's guide ......................................................................................................... 5 Conventions in this user's guide ...................................................................................................... ...

4 Noise performance ...........................................................................................................................................................19 Analog output ................................................................................................................................................... 20 Analog input/output calibration ........................................................... ...

What you will learn from this user's guide This user's guide describes the Measurement Computing USB-1808-OEM data acquisition device and lists device specifications. Conventions in this user's guide For more information Text presented in a box signifies additional information and helpful hints related to the subject matter you are reading. Caution! Shaded caution statements present information to help you avoid injuring y ...

The USB-1808-OEM is a multifunction data acquisition device providing the following features:  Eight 18-bit simultaneous-sampling differential (DIFF) or single-ended (SE) analog input channels – software-selectable per channel as DIFF or SE  Sample rate of 50 kS/s per channel maximum  Analog input ranges of ±10 V, ±5 V, 0 V to 10 V, and 0 V to 5 V – software-selectable per channel  Two 16-bit analo ...

Unpacking As with any electronic device, you should take care while handling to avoid damage from static electricity. Before removing the device from its packaging, ground yourself using a wrist strap or by simply touching the computer chassis or other grounded object to eliminate any stored static charge. Contact us immediately if any components are missing or damaged. Installing the software Refer to the USB-1808-O ...

 Header connectors (2)  Pull-up/down jumper  LED indicators (2)  USB connector Figure 2. USB-1808-OEM components 1 Header connector pins 1 to 28 4 LED indicators (2) 2 Header connector pins 29 to 56 5 USB connector 3 Pull-up/down jumper DIO USB connector The USB connector provides +5 V power and communication. No external power suppl ...

Functional Details 9 Header connectors The header connectors provide the following connections:  Eight DIFF analog inputs (CH0H/CH0L to CH7H/CH7L) or eight SE analog inputs (CH0H to CH7H) Refer to pages 9 and 10 for DIFF and SE pinouts.  Two analog outputs (AOUT0 and AOUT1)  Four digital I/O lines (DIO0 to DIO3)  Two general-purpose counter inputs (CTR0 and CTR1)  Two quadrature encoder inputs (ENC0A, ENC0B, ENC0Z a ...

Functional Details 10 Single-ended mode pinout Terminal Terminal # Label Use # Label Use 1 CH0H AI channel 0 HI 29 NC No connection 2 NC No connection 30 CH7H AI channel 7 HI 3 AGND Analog ground 31 AGND Analog ground 4 CH1H AI channel 1 HI 32 NC No connection 5 NC No connection 33 CH6H AI channel 6 HI 6 AGND Analog ground 34 AGND Analog ground 7 CH2H AI channel 2 HI 35 NC No connection 8 NC No connection 36 CH5H AI channel 5 HI 9 ...

Functional Details 11 Channel-Gain queue The channel-gain queue feature allows you to configure a different gain setting for each channel. The gain settings are stored in a channel-gain queue list that is written to local memory on the device. The channel-gain queue list can contain up to eight unique elements. The channel list must be in increasing order. An example of a five-element list is shown in the following table. Sample c ...

Functional Details 12 Pull-up/down configuration All digital I/O lines are pulled down to 0 V (LO) with a 47 kΩ resistor (default). You can change the pull-up/down configuration using the internal jumper labeled DIO. You must remove the device housing to access the jumper on the circuit board. To set the jumper for pull-up or pull-down, complete the following steps. 1. Unplug the device from the computer. 2. Turn the device ove ...

Functional Details 13 Counter input Counter inputs can be read asynchronously under program control, or synchronously as part of a digital scan group. The CTR0 and CTR1 pins are 32-bit general-purpose counters that can accept frequency inputs up to 50 MHz. The USB-1808-OEM supports the following counter input modes:  Totalize  Period measurement  Pulse-width measurement Counter input modes are programmable with software. ...

Functional Details 14 Quadrature encoder input The USB-1808-OEM can simultaneously decode signals from up to two encoders. Quadrature encoders, 50 MHz maximum pulse frequency, and X1, X2, and X4 count modes are supported. The USB-1808-OEM provides A, B, and Z inputs – ENCxA, ENCxB, and ENCxZ – for each connected encoder. A typical encoder generates the A and B signals at a 90° phase shift with respect to each other. These sig ...

Functional Details 15 Figure 6. USB-1808-OEM PWM timer channel Timer output operations can be paced by the internal clock or by an external clock (OCLKI – refer to Clock I/O below). They can be initiated by a digital trigger (Digital triggering below). Synchronous I/O – mixing analog, digital, and counter scanning The USB-1808-OEM can read analog, digital, and counter inputs, and generate up to two analog outputs and one digit ...

Functional Details 16 In Figure 7 all mask bits are set to 1, so all the bits are included in the pattern to detect. Figure 7. Trigger mask with all bits included In Figure 8 all mask bits are excluded except bit 3. The result of this operation is that only bit 3 is included in the pattern to detect. Figure 8. Trigger mask with some bits excluded Ground The analog ground (AGND) pins provide a common ground for all analog channels. ...

Functional Details 17 Mechanical drawings Figure 9. USB-1808-OEM circuit board dimensions ...

Typical for 25 °C unless otherwise specified. Specifications in italic text are guaranteed by design. Analog input Table 1. General analog input specifications Parameter Condition Specification A/D converter type Simultaneous ADC resolution 18 bits Number of channels 8 differential (DIFF), 8 single-ended (SE); software-selectable per-channel for SE or DIFF Input voltage r ...

Specifications 19 Accuracy Analog input DC voltage measurement accuracy Table 2. DC accuracy components and specifications. All values are (±) Range Gain error (% of reading) Offset error (mV) INL error (% of range) Absolute accuracy at Full Scale (mV) Gain temperature coefficient (% reading/°C) Offset temperature coefficient (µV/°C) ±10 V 0.020 1.5 0.00076 3.576 0.00023 4 ±5 V 0.020 1.0 0.00057 2.028 0.00023 4 0 V to 10 V 0 ...

Specifications 20 Analog output Table 5. Analog output specifications Parameter Condition Specification Number of channels 2 Resolution 16 bits Output ranges Calibrated ±10 V Output transient Host computer is reset, powered on, suspended, or a reset command is issued to the device Duration: 5 ms Amplitude: 2 V p-p Powered off from 0 V output Duration: 20 ms Amplitude: 5 V p-p Differential non-linearity ±0.25 LSB typ ±1 LSB max ...