raffles

Thank you for your help - we have a successful test, now I can finish the programming at least! I'll need to make some time to invest in some learning for this platform for sure!   Cheers

Thanks -I changed that, I still get the timeout errors.  Yes I can setting are correct - I can read/write using my laptop over RS232 So I think I have figured out that I need to write to "Intelligent Function Module", not "CPU Built-in Memory", I no longer have the protocol errors at all, just time out errors which means I have to dig into the wiring again I guess...

Thanks for the response 1) - yes, screenshot attached   2) - Yes and I confirmed by reading from the PLC back as well.   I changed from a single register write to a holding register read and now I don't get the same error.  Instead I now get a timeout error H7D12

Hi guys! I'm sure I'm missing something as I'm not really familiar with Mitsubishis PLC platform, I'm struggling to get Modbus Comms setup. I'm using a R04CPU, with RJ71C24 serial module.  The info available says I should be able to use predefined protocol support for Modbus.  The error message from the GP/CPRTCL instruction is H7FF2(32754) which in the manual is "Communication protocol setting error" - "The instruction cannot be executed with the current communication protocol".  I have a simple single register write setup to try and prove comms before I actually program the rest of the functionality. I managed to get Modbus/TCP setup correctly through the CPU ethernet port, but this is my next hurdle