Most likely there is at least one forced output on the PLC which oddly enough is preventing the situation.  Simulation and real PLCs are not the same when it comes to forcing.

Go online with the physical PLC and disable any forced outputs - provided your process will still function properly with it forced - otherwise, force with new PLC logic.

Mr_Prof

Hi,

I'm trying to download a plc program to an MTP1500 unified comfort. But due to this error (see attached) I'm unable to proceed further.

This error won't show while I'm trying to stimulate it on a web browser with PLCSim.

Just force table.  Watch table has no impact on downloading to the PLC

Mr_Prof

I am unable to go online as well. Tried.
Will removing all the items from my force table and watch table fix the issue?

What are the last few red X entries in the PLC Diag Buffer?  Do any relate to the problem you are having?  Like forces exist, or some PID or T.O. commissioning started but not completed?

Mr_Prof

Tried removing them still the same. Any other alternatives?

Commissioning is a technical term, not an term describing the process of bringing a project or test bed to full functionality.

Enabling a Tech Object (TO) or PID or other similar processing block often have a learning phase Siemens calls Commissioning.  Search the F1-Help in TIA Portal for "commissioning" and "force or forcing or 'force table' " so you see what Siemens is referring to.

If you have actually started the commissioning phase of a VFD or PID controller or even using StartDrive to get a VFD configured and have not fully completed it, you are still "commissioning" the VFD.

Mr_Prof

Commissioning started but not completed - I am able to download the program to the HMI - and want to do the same for the PLC - So that I can see the values actuating for testing purpose.

Also this is a test bed