Usage of Modbus RTU Master and Modbus RTU Client simultaneously

RE: Usage of Modbus RTU Master and Modbus RTU Client simultaneously

Sigurd — Wed, 29 May 2024 10:27:17 GMT

Hi!

We have very limited experience with Modbus on Devzone. I suggest asking about this on the Zephyr Discord:

https://docs.zephyrproject.org/latest/develop/getting_started/index.html#asking-for-help

RE: Usage of Modbus RTU Master and Modbus RTU Client simultaneously

Subu Muthu — Tue, 28 May 2024 17:51:07 GMT

Hi, I would like to implement the same. I tried the above recommendation with the client and server examples from Nordic on 2X nRF52840 DK, one for client and 2nd one for the server. I changed to CONFIG_MODBUS_ROLE_CLIENT_SERVER = y. Both the Client and sever examples worked.

Now I would like to add the server capabilities to the client. Primarily the callback functions needs to be registered so that when the 2nd client sends a message, it is processed. How do we do this?

If I tried to initialize the server, modbus_init_server, after initializing the modbus_init_client using the same iface, the server does not get initialized for obvious reasons - because it the same uart1 interface. The interface is already used.

Looking at the code from modbus_init_server(iface, param) and the modbus_init_client(...) and comparing, they are identical, except that the server include modbus_user_fc and registering the callback functions.

I did search for a combination call back and could not find.

Can you please help?

Thanks.

RE: Usage of Modbus RTU Master and Modbus RTU Client simultaneously

tomtomtom2401 — Fri, 19 Apr 2024 07:16:04 GMT

Thank you!

RE: Usage of Modbus RTU Master and Modbus RTU Client simultaneously

Sigurd — Thu, 18 Apr 2024 10:52:22 GMT

Hi!

I took a look at the configs.

https://github.com/nrfconnect/sdk-zephyr/blob/v3.5.99-ncs1/subsys/modbus/Kconfig#L17

Looks like if you want both client and server, you should not set CONFIG_MODBUS_ROLE_CLIENT and CONFIG_MODBUS_ROLE_SERVER. But instead set CONFIG_MODBUS_ROLE_CLIENT_SERVER=y