9188XT Watchdog issue???

[1984]

Hi community,

I am using an NI 9188XT chassis with watchdog to control an unmanned process. I have configured the watchdog to shut down the DO and AO lines if when the application hangs (timer expires) or on a network loss. I have tested these features and they work perfectly fine.

Whats shocking me - and I really hope I just made a mistake in my code - that if the application crashes (whatever happens with windows for example) then I expected my hardware to shut down according to the watchdog settings but it really doesn't. The timer expires doesn't it? Well... I have found the application gone on the screen but some of the DO lines high.

I have simulated the situation by writing a small rutine which turns on one of the DO lines (turning on a fan) and once the execution reached the watchdog loop I have terminated the process from the task manager. And the fan remained ON! I have also checked what if I break the network connection between the PC and the chassis and then the watchdog worked just fine.

Please help me out here. It sounds unbelievable that if the application crashes then the watchdog doesnt work.

thanks!

[Dsun]

In your code you have it set to triggering on a network connection loss.  Have you tried setting a timeout with the application crash?

[Damian_S]

(deleted)

[1984]

I am not sure if I understand your question.

But to be honest I dont even know what the trigger on a network connection lost means either. If the network connection is lost then the timer will expire anyways so the chassis should enter to its safe state after the initial timeout. Disconnecting the enet cable (so emulation a network loss) does not trigger the watchdog immediately, it still waits until the timeout. So I really dont even know whats that. No matter what the problem I have described works with having that property node and without having it in the code

[Dsun]

Did you make sure that the Watchdog task is started before everything else?  There's a community example with a little note at the end which specifies this.

https://decibel.ni.com/content/docs/DOC-11140

[Hemlis]

I have the exact same problem, did you find a solution for it?

[1984]

Nope, but after filing a support ticket (#7476797) NI confirmed that the problem is reproducible. I am waiting for they answer. Not sure about the when as the confirmation came back to me just yesterday.