Access Inputs/Outputs through Modbus TCP
I looked everywhere and tested several things but cannot figure out a solution for my problem.
At the moment I have:
- PM866 / TP830
--- DI801 (16 channel digital input)
--- DO801 (16 channel digital output)
- CI867 (Modbus TCP module)
I configured the CI867 as a slave and when I create %MW0 in access variables and give it a value I can read the value in an external program on my PC. So this proves communication through modbus is working.
Now i need a way to access the DI801 and DO801 module through modbus, but I cant find a singe way to read (and possibly write, but less important) the IO of the modules.
As my final rack will have several DI801 and DO801's Im looking for the easiest way to communicate all of my Inputs/outputs through modbus.
For Modbus TCP/IP both Master and slave are possible.
If I understood correctly your question - Yon need to connect a variables to your IO Channels and then use their path in Access variables table, to the corresponding name:
IO connection of variables to Profibus DI801:
Access variables tab:
Declaration of the variables in the application: