Watchdog / Comm status

[smolenak]

Hi,

I'm just wondering, what would be the easiest way to check communication status between HMI and PLC (also OPC server), and make alarm of possible comm error? I checked that there is that Communication Error Message system tag, can I use it somehow?

Thanks in advance!

[mark.monroe]

You can add the communication errors system tag. Then have an alarm go off if that number is greater than 0.

If you have multiple controllers and want different alarms depending on what controller is off line, you will need to use the Communication Error Message system tag and write a script to parse the error message. The error message will tell you which controller is off line. You will then need to trigger an alarm based on that. You can trigger an alarm by associating an alarm to a tag, and then increasing the value of that tag so that it triggers the alarm.

There are many scripting examples on the this forum.