- Software
-
Bugs
0
Not a bug
Current loop input fault can't be reset
Current loop input faults, locks up if 4-20mA signal is out of range, will not reset without power cycle, even if the input comes back into range. Can I reset this or disable it without having to cycle power?
Customer support service by UserEcho
This is intentional, the CIN switch off and stay off until the next power cycle, it is done to avoid burning the measurement resistor.
In some earlier versions there was a problem that the overload detection was too fast and reacted to sensor overshoot, from 5.04 the detection was made more robust.
Understood, there is no way to reset this without a power cycle? A very brief (less than a second) pressure surge that causes the input to go slightly above 20mA now renders the system completely inoperable with no way to fix it. Rockwell analog inputs will fault at 22mA, but this will reset immediately once the input is within range again. This is not a good solution since some processes cannot just have their power cycled. At what point does the CIN turn off? Exactly 20mA or more?
On the MC4, the overload detection for CIN comes when it exceeds 25 mA for 20 ms.