Pull-Up/Down Configuration - Measurement Computing USB-1808X-OEM User Manual

USB-1808X-OEM User's Guide

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
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 over and rest the top of the housing on a flat, stable surface.
Caution! The discharge of static electricity can damage some electronic components. Before removing the
USB-1808X-OEM from its housing, ground yourself using a wrist strap or touch the computer
chassis or other grounded object to eliminate any stored static charge.
3. Remove the rubber fee from the bottom of the device, and the four screws using a #1 Philips head
screwdriver.
4. Hold both the top and bottom sections together, turn the device over and rest it on the surface, then
carefully remove the top section of the case to expose the circuit board.
Figure 4 shows the location of the
5. Configure the
DIO
6. Replace the top section of the housing and fasten it to the bottom section with the four screws.
For more information about digital signal connections
For general information about digital signal connections and digital I/O techniques, refer to the Guide to DAQ
Signal Connections (available for download at www.mccdaq.com/support/DAQ-Signal-Connections.aspx).
jumper on the circuit board.
DIO
Figure 4. Pull-up/down jumper location
jumper for pull-up or pull-down, as shown in Figure 5.
Figure 5. Pull-up/down jumper configuration
. You must remove the device housing to
DIO
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Functional Details