Hello!

I am using the Modbus TCP driver to communicate with Schneider Electric PowerLogic / Micrologic MTZ breaker with ethernet communication module. The breaker's Modbus Standard Address is locked at 255. From the instruction manual (see image below), the Modbus TCP driver only supports addresses 1-247.

Is there some type of expression that can be used to have the Modbus TCP driver communicate with the breaker? The image above mentions expressions, but says "Procced with caution."

Any assistance would be appreciated.

On my version 12.2.09 I can select "Constant", "Expression", or " Tag". I'd probably select tag and link it to a memory tag that I can set. If you select expression, then click the small window box that appears, then type in 255. On my version it automatically sets it as a constant at 255 (which typically cannot be input...).

I suspect the warning is more to do with the fact that the addresses 248-255 are reserved by the modbus standard and are not defined as standard station addresses... though if the device is locked at this and you don't have multiple devises with the same address then let us know how it goes.

Thanks for the suggestion. I will give it a try!

As Tom noted, this is designed to help prevent folks from entering values outside of the Modbus spec but VTScada does allow any value to be entered as an expression. In your case, click to make an expression and in the expression editor, simply enter 255. It will be placed at a constant and you should be good to connect to your device.