mrmss
Lifetime Supporting Member
Hi,
I'm trying to integrate an MVI69-MCM module into my project. I need to be a Modbus slave and I need to send and receive data. I'm really confused about how the Modbus addresses map to an Address in the PLC.
Anyone have an example they could run me by?
Main area of confusion I think is with the Backplane Read Register. Following the example I end up with an address of 500 but nothing I change in my Modbus Master simulator shows a change in the PLC. I changed this address to 300 and I can see values I change being written into the PLC, however if I write certain registers I end up clearing a different register - which implies I have an overlap.
I have my Backplane Write Register set to 0 and 200 values, this works perfectly fine.
A sample project with some documentation would be great help.
I'm trying to integrate an MVI69-MCM module into my project. I need to be a Modbus slave and I need to send and receive data. I'm really confused about how the Modbus addresses map to an Address in the PLC.
Anyone have an example they could run me by?
Main area of confusion I think is with the Backplane Read Register. Following the example I end up with an address of 500 but nothing I change in my Modbus Master simulator shows a change in the PLC. I changed this address to 300 and I can see values I change being written into the PLC, however if I write certain registers I end up clearing a different register - which implies I have an overlap.
I have my Backplane Write Register set to 0 and 200 values, this works perfectly fine.
A sample project with some documentation would be great help.