LinuxCNC is Running......?

I've been looking for a signal in hal that activates the moment the interface(EMC2) is executed and stays on until it is terminated. My intent is to use that signal to notify the PLC that the interface has dropped out. I've been looking for it. Maybe its right in front of me and I dont see it.

Right now as is stands, the PLC will enter fault status once the drives indicate a following error, which safely stops the machine but I would like to add that signal to my control loop and have a unique indication.

Thanks, Ben

Thank you Tommy.

I thought maybe something was in the default servo thread I wasn't seeing.

I imagine I could add it to the servo thread instead of adding a base thread. I do not require a squarewave pulse. A digital signal will suit my purpose.

I dug into the functions man pages once you mentioned the charge pump. It looks as if the watchdog.ok-out (if enabled ) will serve my purpose very well.

Looking at the mesa watchdog function....it has a pin has_bit, I will work off this for now and report back.

Seeing as has-bit kills all outputs to original state that wont quite work. I have set an output true when the thread starts. That will be enough for now.

You are correct. In the 10+ years I have been running machines on this interface I never had a failure due to emc2. I've had a few PC power supply failures and brain farts are ten fold.

My current setup signals an Estop to the PLC in the event of an ethernet disconnect or a PC crash. And thats what I need.