Suppressing alarms from S7 driver

[siemens_dva]

Hello there,

we are currently using the old S7 driver to connect to a S7-400H system. All alarms and messages are received via multi-instance alarms from alarm_8ps. Each alarm_8p has 8 signals that can generate a message.

Is it possible to suppress individual signals/messages from an alarm_8p instance in WinCC OA? I couldn't find a way to do so in the alarm system and disabling the alert handler would disable all alarms from that instance.
As far as I understood the alarms are generated directly by the driver through the multi-instance alert handler. If there is no default way to disable single alarms, is it maybe possible to hook into the alert generation to filter out alarms with a custom script?


Greetings
Don

[Gertjan van Schijndel]

From the S7 driver specialist:

I don't know any possibility to hook into the process of alarm-reception, also the alert-filtering in sum-alerts won't work for the customer as all single alarms of the alarm_8p block are received on the very same DPE.

In my opinion the customer might either use some alertConnect() and "remove" alerts right after receiving them, identified by some own logic, e.g. the signal-number. Or he splits the alarm_8p call in the PLC program into two separate calls with one for the interesting alarms and the other one for the uninteresting alarms, he does not want to get in WinCC OA.

[siemens_dva]

Thank you for the reply. This might be a sensible solution, if it is possible to completely remove alarms from the system.

I tried to find functions for this purpose in the documentation but couldn't find a way to remove existing alarms.
I have been looking under "Modul PARA -> Datenpunktkonfigs -> _alert_hdl" but was only able to find documentation and examples to create or acknowledge an alarm. Can you give me a hint?