Use PCM port of M66

Hello. I have module “Quectel M66” I want to use it to transmit voice signals during calls over PCM. I used the command “AT CHFA = <4>” to switch the signal to the PCM channel, but the call over the PCM channel still failed. I wonder if Quectel M66 supports calls over PCM? Looking forward to receiving your help. Thanks!

Has anyone done and know about this problem please help me.

please use the below command to set up the PCM
for description of these command please refer the page no 48 and 49 of the attached pdf.

Also please help to share the current firmware version of the module, you can check it using ATI command.Quectel_M66_R2.0_Hardware_Design_V1.0.pdf (906.7 KB)


Thank you rahul.mahakalkar!
Let me check. If have any problems I will ask you.