
■Use individually shielded, twisted-pair wires to connect AI signals to the
device. With this type of wire, the signal attached to the positive and negative
inputs are twisted together and then covered with a shield. You then connect
this shield only at one point to the signal source ground. This kind of
connection is required for signals traveling through areas with large magnetic
fields or high electromagnetic interference.
■Route signals to the device carefully. Keep cabling away from noise sources,
such as video monitors and analog signals.
Use the following recommendations for all signal connections to the NI PXIe-7865:
■Separate NI PXIe-7865 signal lines from high-current or high-voltage lines.
These lines can induce currents in or voltages on the NI PXIe-7865 signal lines
if they run in parallel paths at a close distance. To reduce the magnetic
coupling between lines, separate them by a reasonable distance if they run in
parallel or run the lines at right angles to each other.
■Do not run signal lines through conduits that also contain power lines.
■Protect signal lines from magnetic fields caused by electric motors, welding
equipment, breakers, or transformers by running them through special metal
conduits.
■To minimize signal-to-signal skew within each digital channel, maintain
signal lines' length within 1 inch of dierence.
+5 V Power Source
Use the +5 V terminals on the I/O connector supply +5 V referenced to GND to power
external circuitry.
Caution Never connect the +5 V power terminals to analog or digital
ground or any other voltage source on the NI PXIe-7865 or any other
device. Doing so can damage the device and the computer. National
Instruments is not liable for damage resulting from such a connection.
The power rating is 4.75 to 5.1 V DC at 0.5 A.
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PXIe-7865 Features