MUX mode in EC21

IoT Modules
1

Hello.

I am working on a system that uses an EC21-EFA-512-STD module. We need to use the mux mode but I have not found information about the subject when searching the documents. I have ported a library that works ok with the BG95 and BG96, but with the EC21 there is not answer from the modem after sending the first sabm channel creation command.

When using the AT+CMUX command, the response obtained from the EC21 is slightly different from the one given by the BG96, so I presume there are differences in the protocol between the two models. Bui I have not been able to find the required documentation.

Any help will be welcome. Thank you for your support.

2

If you want to use CMUX for EC21, please make sure the RTS pin is low.
It is the bug of the EC21 chip/

3

Thanky you very much. I pulled RTS low and everything is working now!