Communication Failure Indication

Communication Failure Indication

Dear all,
I have a Bool variable for Communication status.
If Communication failed then Bool value = 0 otherwise 1.
Our field device is holding the last values even in communication failed condition.
But we have to change the values to ***** or in some different characters in SCADA side while communication failed (If Bool value =0).
Can you please explain how to do this?

This is a migrated post! Originally posted on 27.08.2013 by user navaneet. Please be aware that information can be outdated.