Question

Hey everyone!

I am new to working with modems and RS485, but i hope my question will be clear!

I connected the RUT955 through RS485 with a EtherCAT Terminal (EL6021 from Beckhoff) to a PLC. Now I try to send an SMS via the modem. If I try to send an SMS in the WebUI it works fine, but i can't get it work by sending AT commands.

I got already support from Beckhoff, so I am pretty sure this part is correct, thats why I guess I have some wrong settings on the modem... Also the I/O of the terminal shows that some informations are send and recieved, but in the Log of the modem there are no messages.

Could somenone help me and provide me some further informations on what to pay attention when I connect the modem with RS485? Which settings are needed?

Thanks!

Answer 1

Hello,

Could you share, how exactly are you sending the SMS?

What errors do you receive? 

What is your RS485 configuration?

Could you try the following AT commands:

AT+CMGF=1

AT+CMGS="phone_number"

Best regards,

Comments

Hey, thanks for the response!

As I am using TwinCAT, I use a function block which is already delivered by Beckhoff (Link to description). But as this is not working I am trying to setup a communication by sending AT commands, where I am still working on. As soon as I finished those, I woll try your suggested commands.

This is my RS485 configuration:;
Enable: ON
Baud rate: 9600
Data bits: 8
Parity: None
Stop bits: 1
Flow control: None
Serial type: modem
Mode: Full control
Full Duplex: ON

The problem is I recieve no error. From the plc side the message is send, but no communication reaches the modem, so no SMS is send.

Thanks!