Detecting an SCXI failure

[Nick_S]

Im using an SCXI chassis to read temps/voltages and instruct a hydrogen generator.  One time the SCXI froze up or the main cable from it to the computer system may have come disconnected.  Is there some kind of a handshake method in Labview to check on the SCXI to verify it is still operating properly or must I just interpret the data I'm receiving from it.  I need to have an indicator in order to shut down my generator.  Any known software checks that can be done using a canned VI?  Thanks

[devchander]

Would not checking the error output from the 'Reading the Temp and Voltage' part of the code, be an indicative that something is wrong in the SCXI chassis section??

[Jennifer O]

Hello Nick,

Unfortunately once acquisition begins, no error messages are thrown when the cable from the PCI or PXI module gets disconnected or power is lost to the SCXI chassis.  Therefore the only test would be to catch a condition where unexpected data was being returned.  In this case the task can be stopped and restarted.  At this time, communication will be verified and an error will report if communication cannot be re-established.

Alternatively the SCXI-1600 USB option is directly installed inside the SCXI chassis.  If the cable is disconnected or power is lost, there is no communication to the DAQ board (the SCXI-1600) and therefore an error will be thrown.

Hope this helps,

Jennifer O.
Applications Engineer
National Instruments