Modbus Bridge- Question

[wjohn007]

Hello joerenst,

if I understand correctly, the code for the Modbus bridge (Tasmota) came from you.

Thank you very much, this function is really helpful.

What is the use case for the 'ModbusTCPConnect' command?

John

[jeroenst]

ModbusTCPConnect ,<ip_address> = connect to a remote Modbus TCP server on remote tcp port˙ and ip_address

I believe it was a request from some user who also tested it. I never used it myself though.

[wjohn007]

Thank you for your response.

From my point of view, this command only makes sense if the external device coupled via the serial line is a Modbus master and its request is sent to the TCP/IP Modbus slave.
This would require a TCP client connection, which the ModbusTCPConnect command provides.
But this scenario doesn't work. Error 'NoDataExpected' appears in logging.

[jeroenst]

Tasmota is always master on the serial line modbus and a modbus slave on the network in the current design.

So it can connect to an external tcp device and waits for modbus data from the tcp master. I could imagine this like a serial to tcp converter connected to a modbus master device.

So the use case provided above is indeed not yet supported.

Currently I don't have the time to make this extra functionality but feel free to make a PR.

[wjohn007]

Thanks again for the quick reply.
Do you agree if I copy excerpts from our conversation into this ticket
arendst/Tasmota#22689
so that other users can also benefit from it?

[jeroenst]

Perfectly fine for me.