I created a digital control tag that is interfacing with an Allen Bradley Micrologix 1100 PLC with the DF1 driver. When I select the newly created button I receive an "Error Code 256" for this button. What does that error code mean? I have several other buttons on the same screen controlling bits in the same plc and without any issues.

The 200 series error codes are returns from the PLC itself. I don't see anything in the Rockwell documentation regarding 256 (0x100) so it may be new.

If you draw the Show Stats for the driver, does it indicate any error message to go with it?

What address are you trying to read?

In my experience with Allen Bradley Controllogix processors I've noticed the "256" code is returned on two occasions:

• The tag does not exist in the PLC tag data base (check that the proper syntax is used)

• Communication lag is causing the a non response from the PLC regarding that particular tag and VTScada throws an error.

I'm still just a novice with using VT so i'm not sure of the exact definition of the error but these have been two situations where I have encountered the error.

What address Data file are you using?