At a plant site, I have come across a large number of Device Control points that have their Fail_alm disabled. These are momentary points and when I enable the points, the fail alarm is pretty much always active (even though the confirmed/desired states are correct). Any thoughts as to what we can do to make the alarm come in when there is an actual failure?
Have you looked at the DC block device options (DEVICE_OPTS)? There are two parameters that may be of interest when you momentarily energize an output to achieve an Active state: Passive when Confirmed — When the Passive when Confirmed option is enabled (True) and the field device is confirmed to the desired Active state, OUT_D is changed to the Passive state. Passive on Active Timeout — When the Passive on Active Time-out option is enabled (True) and an Active state is not confirmed within the confirm time following a command to an Active state, OUT_D is changed to the Passive state.
There are several different conditions that may cause FAIL_ACTIVE to be true. When FAIL_ACTIVE is true, what is the value of FAIL parameter for the DC block?