Appendix C Common Questions
SCXI-1503 User Manual C-2 ni.com
Can I connect N current-output channels in parallel to create a
precision current source that provides N × 100μA?
Yes, you can connect the current output in parallel. When connecting the
output in parallel, connect the appropriate IEX+ terminals together and the
corresponding IEX– terminals together.
Can I connect N current-output channels in series to achieve a higher
terminal-voltage compliance limit?
No. Each current source is ground referenced. Therefore, you cannot place
multiple current-outputs in series.
Are the SCXI-1503 channels isolated with respect to each other, the
E/M Series DAQ device, or ground?
No. The SCXI-1503 does not contain any isolation circuitry. If you require
isolation, consider the SCXI-1124 or SCXI-1125 module instead.
Can I modify the SCXI-1503 circuitry to generate current at a level
different than 100μA?
No. Do not attempt to modify any circuitry in the SCXI-1503.
Are there any user-serviceable parts inside the SCXI-1503?
No. There are no fuses, potentiometers, switches, socketed resistors, or
jumpers inside the module. Disassembly of the module for any reason can
void its warranty and nullify its accuracy specification.
Can I access the unused analog-input channels of the E/MSeries DAQ
device if it is directly cabled to the SCXI-1503 in a single-chassis
system?
Yes. E/MSeries DAQ device channels 1 through 7 are available to measure
unconditioned signals. Use an SCXI-1180 or the 50-pin breakout connector
on the SCXI-1346 or SCXI-1349 cable adapter to route signals to these
channels.
Which digital lines are unavailable on the E/MSeries DAQ device if I
am cabled to an SCXI-1503 module?
Table2-4 shows the digital lines that are used by the SCXI-1503 for
communication and scanning. These lines are unavailable for
general-purpose digital I/O if the SCXI-1503 is connected to the
E/M Series DAQ device.