ABB 800Xa 6.01 CI840 primary ans 2ndary loop status monitor

[azgor_03]

We are using ABB 800xA 6.01 CI840 as a retundand system
Here we want to monitor and generate alarm if one of primary or secondary loop fails.
how to clarify status bit of CI840 if only primay loop fail or secondary loop fail.
Now we are able to monitor if both loop fails.