Hello
I am continually staring at an abundance of Fail Alarms for motors and sadly very few of them have actually Failed but rather have been shutdown on an Interlock Condition and these cause a Flood of Alarms.
What I am interested in doing is adding an integer to our interlock composite so that I can identify interlocks that are External to the motor (from other motor conditions) vs interlocks that are directly associated with the motor (High Temps, High Amps, Speed Switch, Alignment Switches, etc). I would then like to intercept an External Interlock and stop it from Failing the motor (If the Motor Fails to Stop then I would consider that a motor failure but a successful shutdown do to an interlock, in my opinion, does not need to be considered a failure) and instead Stop the motor.
I have tried a simple Pulse interception (Blocking the Interlock & Permissive Inputs for a scan while I send a Stop command to the motor) but this does not seem to work as a Stopping Motor that gets an Interlock Shutdown will still flag a Fail Alarm. I was hoping this would function as the operator would not be alarmed but would see the motor Stopped and No Permit for that motor - Aditionally the operator can look at the Interlock Details and see what stopped the motor. Of course the Motor that did experience a direct Failure would still alarm and this is where the operator should be focussed. UPDATE- this did not work as CAS mode becomes disfunctional. I will try feeding the Fail Alarm status to a conditional DI alarm and see if that works.
Anyone have any details on what actually constitutes a FAIL Alarm on a DC Block (I am assuming by my issue it is anything other then a Passive PV and an Interlock Shutdown) )and it there is any way to avoid it in this case other then to delay the Interlock Shutdown until the motor is fully stopped?
I realize this will open a can of worms regarding alarm philosophy but really in systems with cacading conveyors and the like - why do we need a bunch of motor failures when really only the first one tripped out?
I would also prefer to have conditional alarm strategies in the module or as close to the module as possible and sadly our DC Block does not offer Conditional Alarming (on the V13 system - not sure about newer varsions).