Tag Values for Alarming on Redudancy

[kruse.andrew]

Alerting On Redundant System

We have a redundant 7.3.2 system and our customer wants an alert email when the Master server falls over. What is the best tag to set up, ie. there are a number of system tags under the redundancy section (ActivityLevel, IsActive, IsMaster, Role), but how do these behave if the master falls over. Does the Role = Backup , IsMaster = 0 and IsActive = 1 If so then can I do an expression tag based on this condition to send out an alert email.

What is the values for these tags when the redundant system becomes active?