Hello,

OCM parameters (Operator Control and Monitoring) are being changed often. The system does not read back those values. They exist in the PLC but upon restart (full download) they change back to default values.

There is a function called: Readback which allows the user to readback parameters from PLC back to the CFC program. This way, you ensure you have the latest values, but this must be done manually, so a readback must be done often. 

This also includes parameters like gain settings for a PID controller. 

The readback can be initiated via CFC->Chart->Read Back

 Hi,

One important note: Cold restart is not permitted for AS in PCS7 environment, only Warm restart. With Cold restart start values are being reloaded to the program resulting in possible plant error state. 

See the following FAQ for information what the Warm,Cold,Hot restart modes do. Please only use Warm restart. 

You have different options for readback. It is possible to read back all data (not just only OCM (operator) parameters. Below is a manual to get data that is not taken into account by the readback.

Read out data that is not taken into account by the readback 

Douggy

Hello,

In my PCS7 project, I performed a readback function to make an offline copy of a selection of parameter values. I then stopped the PLC and performed a Cold Restart (customer's request). Once the PLC had restarted the parameter values had reverted back to their initial values. I then had to perform a PLC download to restore the values that were previously readback. Is there any other way of doing this? By that, I mean can readback values be automatically restored after a Cold Restart?

Thanks in advance.