Hysteresis / Deadband for process gateway signals
Hi,
I'm trying to achieve a 'deadband' on analogue inputs sent via DNP3 outstation from process gateway. Support have confirmed that PG doesn't have such a feature so I have requested that be added to roadmap for future.
In the meantime I'm trying to test best workaround i.e. take input values from process drivers (61850 and DNP3) and copy them to a temporary variable which can have hysteresis applied (which will be my output deadband).. this temporary variable will then be mapped to process gateway.
I'm doing some testing with an internal variable, but the hysteresis never seems to work.
Set up as follows VAR_INPUT - internal variable, no hysteresis applied
VAR_OUTPUT - math driver mapped so it is =VAR_INPUT, but with hysteresis applied. Problem is that the hysteresis is ignored.. every change is mapped through to VAR_OUTPUT. I also tried using the ADP driver, but it's exactly the same. Is there a correct way to map 1 variable to another and have the hysteresis work?
Ive looked at the other threads on hysteresis and 850, but they don't solve my use case.
Note I want the input variable (which is what I display on HMI) to always change when the process changes, it's only the variable sent via PG that should have hysteresis applied.
Prefer to not use VBA to achieve this if possible, but welcome any suggestion.
Note I have seen this work before, but it was on a Sicam 720 project so not sure what drivers were used.
Thanks,
Dave
This is a migrated post! Originally posted on 12.06.2019 by user HMIdeveloper123. Please be aware that information can be outdated.