National Instruments NI 2590/2591 - Manual (Page 33)

© National Instruments Corporation C-1 NI 2590/2591 User Manual
C
Common Questions
This appendix addresses common questions you may have while using
your NI 2590/2591 switch module.
What should I do if the software detects the module but the switches do
not switch?
Verify that the switches do not switch. Close your application program
and then launch the soft front panel as described in the Set up and Test
document you received with your kit. The soft front panel shows the state
of each relay on the module. Try closing and opening the switches.
Also be sure to check the return codes of the NI-Switch operation to ensure
that there are no errors (negative value) or warnings (positive value). You
can also use the NI-Spy utility to check for error codes.
Finally, verify that your code is correct. For reference, see the examples
described in the NI-SWITCH Software User Manual. The NI-Switch driver
also ships with several examples in source code. Compare your algorithm
to those in the examples.
What should I do if scanning does not work?
First, ensure that you have configured the switch module and the instrument
to match trigger lines. The output trigger of the instrument should connect
to the trigger input of the switch module. In addition, the scanner advanced
trigger of the switch module should be connected to the input trigger of the
instrument.
If the switch module is used to initiate the scan, make sure the scope or arb
is waiting for a trigger before enabling scanning on the switch module. This
is the recommended method for hardware scanning.
If the scope or arb is used to initiate the scan, enable scanning on the switch
module before configuring the scope or arb to start taking measurements.
Also be sure to check the return codes of the NI-Switch operation to ensure
that there are no errors (negative value) or warnings (positive value). You
can also use the NI-Spy utility to check for error codes.