I guess you want to detect one controller from another controller and do some programming based on that, I can add this to our list. There is an alarm generated by the controller when other controllers go offline, I will have to ask my crew about the details of that.
Important Note: It is good practice to have key IO wired to a single controller so that a network outage doesn’t create havoc. If you do rely on the network for critical info make sure to have logic that lets the system degrade gracefully.
There is a command called power-loss, it evaluates to TRUE (1) on the first time the program runs it, after that it evaluates to FALSE (0). I have to confess we haven’t tested out this command on the latest hardware, we’ll get it working.