©NationalInstruments Corporation C-1 NI2590/2591 User Manual
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Common Questions

This appendix addresses common questions you may havew hile using
your NI 2590/2591 switch module.
Whatshould I do if the software detects the module but the switches do
not switch?
Verifythat the switches do not switch. Close your application program
and then launch the soft front panel as described in the Set up and Test
documentyou receivedwith your kit. The soft front panel shows the state
ofeach relay on the module. Try closing and opening the switches.
Alsobe sure to check the return codes of the NI-Switch operation to ensure
that there are noerrors (negative value) or warnings (positive value). You
can also uset he NI-Spyutility to check for error codes.
Finally,verify that your code is correct. For reference, see the examples
describedin the NI-SWITCH Software User Manual. The NI- Switch driver
also ships with severalexamples in source code. Compare your algorithm
to those in the examples.
Whatshould I do if scanning does not work?
First,ensure that you have configured the switch module and the instrument
tomatch trig ger lines. The output trigger of the instrument should connect
tothe trigger input of the switch module. In addition , the scanner advanced
triggerof the switch module should be connected to the input triggerof the
instrument.
Ifthe switch module is u sed to initiate the scan, make sure the scope or arb
iswaiting for a trigger before enabling scanning on the switch module. This
is the recommended method for hardware scanning.
Ifthe scope or arb is used to initiate the scan, enable scanning on the sw itch
module before configuring the scope or arb to start taking measurements.
Alsobe sure to check the return codes of the NI-Switch operation to ensure
that there are noerrors (negative value) or warnings (positive value). You
can also uset he NI-Spyutility to check for error codes.