Short answer:
Currently you can not change the process number (ParCfg.ProcessNo) of a WorkProcess add-on at runtime.
Detailed answer:
The term "multi process" can have different meanings:
- Usually it means that one process is executed several times with the same process number. This would be possible with the current add-ons.
- The WorkProcess add-on is designed to represent one process. Sometimes there are processes in a station that have the same result data. We explicitly don't want to have one WorkProcess add-on for several processes, just because the result data are identical.
- One physical process is executed several times with different MES process numbers, e.g. process number 111 for the first time of the cleaning process (afterwards the work piece sees further processes), then process number 222 for the second time of the cleaning process, etc. For this use case a change of the process number would be necessary on PLC side, but currently not possible. That means you need 2, 3 or more add-ons depending on the maximum number of the process cycles. This is not very smart and a PLC update would be necessary everytime a further cycle / process number is added on MES side.
The official workaround for such limitations: Add your own ProcessNo variable to the output structure. The MES engineer then must use this process number (that can change in every command) instead of the default process number of the Public Interface profile.
From the fuel cell project there have already been other requests in the past to make the process number changeable in the PLC. Are you also part of this project?
Then it makes sense to make a meeting to discuss the current process concept.
