Question

Hello,
with RUTX11 the MODBUS TCP SERVER is not working for me.
When I try to read holding register 203 or other I am getting less bytes than it should be
according to MODBUS protocol.
Can please reply if is known issue or there is somenthing that I miss?

Thanks

Best Regards
Andrea

Comments

Hi Andrea,

I work on a lot of PLC and Modbus TCP/RTU Protocol converters at work.

Maybe one possibility if you are polling from a PLC that does byte swapping - where the least significant bit is swapped around thus giving a totally wrong value.

Just a thought.

Cheers

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Hi,
I am using ModScan32 and ModPoll for testing purpose and I am getting the same error.
I use that software also at work with no issues with PLC and othe MODBUS TCP Server.

I can make some investigation analyzing protocol but I have no time for it.

Thank you for answer.

Best Regards
Andrea

Answer 1

Hi,

On RUTX11 register with address 203 is responsible for setting Wi-Fi on/off.

This register doesn't support read function and you can only write to it to Enable/Disable Wi-Fi on your device.

Comments

Hi,
I add also custom registers and I have the same error in reading.
With custon registers I should be able to read right?

Andrea