Modbus TCP server Send SMS error code 3

[rra]

Hi
I’m trying to send SMS with the Modbus TCP server interface. When i write single holding register “Send SMS” 397 value 1, I get modbus error 3 (invalid modbus value)

Setting the text and phonenumber register 398 return error code 0, No error.

I’m using the RUT200.

Why am i not allowed to write value 1 to register 397?

[Ronno]

Hi, I have the same problem.
I am completely unable to use the modbus server to send SMS. It seems register 397 doesn’t exist…
But it’s working well if you use the modbus client of the modem (see on wiki https://wiki.teltonika-networks.com/view/Modbus_TCP_Server_Send_SMS_example).

I tried installing tcpdump on the modem to check the modbus request and send it from modbus doctor (a modbus client), but it appears to send a POST request to a specific URI instead of modbus TCP.

I have the feeling that this modbus server just doesn’t work without the modem’s modbus client

If someone from Teltonika could check that, it would be very much appreciated.

Thanks, have a nice day !