Self-Test Function for NI-Switch Driver

Issue Details

What does the Self-Test Function in the NI-Switch Driver test for?

Solution

The function in the NI-SWITCH instrument driver called niSwitch_self_test() (niSwitch Self-Test VI in LabVIEW) does the following:

For SCXI switches:
When the SCXI chassis is powered on, a module ID number is written to a register on the SCXI hardware automatically, and this number is also cached in computer memory when the NI-SWITCH Initialize function is called. When the self test function is called, NI-SWITCH reads the module ID from the SCXI register and compares it with the module ID that's been cached in memory. If they're the same, the self-test passes.

For PXI switches:
When the NI-SWITCH Initialize function is run, software is automatically loaded onto an FPGA in the PXI module. When the self test function is called, NI-SWITCH checks this FPGA code and makes sure it is ready to receive Connect and Disconnect commands from the NI-SWITCH driver.