watchdog USB 6525

[Randall_T]

I need to return the outputs of my USB 6525 to a safe state in case there is a software communication problem.

Basically I need to sent close the relay for a short period  .5 sec to .25 seconds then open the relay. I can do this by writing in a for loop close then delay for the milliseconds needed then open on the 2nd iteration.  This works good except should the software or computer loose communication to the device the relay would remain closed and cause an unsafe condition.

 The literature states you can do this by setting a watchdog timer but I can not find how to configure this. The way I understand it once the watchdog is set if it does not receive a reset from the software in the determined time it will set the output to what is determined the safe position.

Anyone have an example of how to configure this device.  By the way I would also like to do this with an SCXI 1163R also.

Another alternative would be to send out a pulse over a specific duration but I don't believe the 6525 allows hardware timed execution.

Thanks for any suggestions.

Randall

[Blokk · Accepted solution]

There are DAQmx watchdog timer VIs. If you have the DAQmx driver installed (device drivers installed), you can easily setup and use such timer. Their VIs's help are very self-explanatory.

http://zone.ni.com/reference/en-XX/help/370469AF-01/lvdaqmx/mxcreatewatchdogtask/

[Randall_T]

Thanks,

I can not believe that I missed this pallet. I searched the LabVIEW help but must have split the watch and dog up when I did. I appreciate your help.

Randall