How do I drop all outputs out/off when my vi stops running?

[JShaw]

Hello,

I noticed when I stopped running my vi (targetted to RT) from my host computer that my program in the FP2020 continues to run, ie. all outputs that were on stay on. I'm used to the PLC world which stops all outputs  when program is stopped. Is there a way to accomplish this with my FP2020 I/O?

Regards,

John

[Michael.Phillips]

John,

Thank you for contacting National Instruments.

The easiest way to accomplish setting all your outputs to off is to do it in your VI. If you include a "stop" button in your VI, you can do an FP Write that sets all the outputs to zero after the stop button is pressed.

[JShaw]

Hi Michael,

Yes I have this, but I have on occasion lost communication to RT from my host and I would like to have the program stop by itself as I have no control over my test stand when this happens other than throwing main electrical switch. I have many programmed in safety shutdowns but would still feel better if it dropped out it's outputs, digital and analog. Any ideas?

John

[Michael.Phillips]

John,

There is a feature that solves this exact issue. It is called a Network Watchdog, and you can configure it in Measurement & Automation Explorer. You can set this up to set your outputs to chosen values whenever you lose network connection for a specified amount of time.

There is a tutorial on configuring the FieldPoint Watchdog at http://zone.ni.com/devzone/conceptd.nsf/webmain/fb7aabacc2bab99686256c7e0080e60a

You have to enable the network watchdog for the FieldPoint bank, then enable the watchdog for the modules you want and specify values for each channel.

[JShaw]

Hi Michael,

I set up watchdog stuff in Max as it says and set my output card's outputs to "enable" for watchdog and the value of zero. It only works when I run it in Max. When I turn on an output then remove ethernet cable from FP2020 it shuts off my output after 2000ms as I set it for. When I run my vi for the stand and pull out the ethernet cable it shuts off my output very breifly than it comes back on. I am not sure why. Do I have to have the RT watch dog vi's in my main vi that is running on the FP2020 also? If so what is the easiest way to monitor traffic then shut off my outputs after X seconds using watch dog vi's?

Thanks,

John

[e-Cash-Money]

Hello John,

Did you make sure to save after you applied the watchdog settings?

Also, when you are running the VI, is the block diagram downloaded onto the controller and running on the controller or are is the block diagram code running on the host PC?