Why did it go Critical?

Critical state is meant to be the last limit that for example should be used to trigger a circuit breaker.  

The Critical state is managed using the critical control logic 

If item is in critical state then the icon below will show and Mode will be in the OFF state

 What to look for:

Items highlighted in yellow are items that are set: Monitor to ON plus the Threshold has been breached.

Mode will move to OFF state if any one monitored threshold has been breached. 

State column has blue check box for OK state and blank where Threshold has been breached.

Note:  Extra Parameters has some possible fields that might have been breached.

Extra Parameters

It's back within limits now.  How do I find out what went wrong?

Whenever a critical event occurs a snapshot report is generated automatically.  This records the state of the batteries at the time it went critical.

It is then just a case of looking at the critical settings you have on your system and comparing them to what the system says was happening at the time to find which limit was breached.