Hello,
I am using Modbus RTU over TCP through the OPC interface of course. I cannot see an easy way to setup reading from one address and writing to another. The only thing I found was using the OPC tag write and putting in the write address specifically for each write tag.
Is there a better way to specify the read vs. the write address when they are different? That seems very tedious and clunky to do it that way.
No, this is a pretty uncommon scenario and not supported directly in the tag system.
I’d set up a tag for the read address, make it read only in Ignition as well if it’s not already read only in Modbus by virtue of being an Input Register or Discrete Input, and then any time you need to write just do it via script with system.opc.writeValue.