Hello,
I would like to know what is the difference between a PG connection and an OP connection for the CPU load and the effects on the cycle time.
Because for the diagnotic of my process, I use the software IbaPDA on a card CP443-1EX11 and in this software, one can configure the connection of the two ways.
But who will take the least CPU load?
Thank you

Hello Damall

The PG Connection is made for loading PLC Blocks of going online with your Simatic Manager of TIA Portal.

A OP Connection is made for communication issues like HMI Communication.

I do not know which one is faster than the other. I think you have to try and have a look on your cycle time.

Bye Murof

From my experience there is no difference. You can also use programming functions using OP connection ressource. From what I guess this is mainly for reservation of connection ressources. If you reserve always one connection ressource for the PG connection, then even if there are too many HMIs for example using the OP connection to it's limits, you can always go online with your PG.

In my opinion it's a bad behaviour when an application which acts as OP (using only variable services) is using a PG connection ressource.

Hello Damall,

nice to hear that you are using ibaPDA, hope everything works as expected and it is a great help!

There is no technical difference between the 3 connection types PG, OG, other. It is just as already Thomas_v2.1 explained, it is possible to reserve connection ressources of certain types, e.g. to ensure that there is always at least 1 ressource left to connect a PG. This should be taken into account, when selecting the type.

Dear Damall

As SIEMENS documents mentioned, OP Communications provides functions requited for monitoring and modifying, while PG Communications provides functions requited for downloading/uploading, configuration and testing.