We can see the timers running and the timer done bits energizing the rungs for both READ and WRITE message blocks.

We’ll enter a value in the Local PLC1 MSG_ME_to_REMOTE_DINT tag of 3333 and observe the communication to Remote PLC2 MSG_REMOTE_to_ME_DINT tag value changed to 3333.

In this case, the WRITE message block in the Local PLC1 does all the work without any configuration or programming required in the Remote PLC2.

We’ll enter a value in the Remote PLC2 MSG_ME_to_REMOTE_DINT tag of 4444 and observe the communication to Local PLC1 MSG_REMOTE_to_ME_DINT tag value changed to 4444.

Again, the READ message block in our Local PLC1 does all the work without any configuration or programming required in the Remote PLC2.

If you know the PLC and Tag name, you can READ or WRITE to and from any Controller tag.