problem with UART2


Hi ppl! The problem is - i can’t activate UART2 in my Q2687. I sent at+wmfm=0,1,2 and the answer is ERROR, without any error code. When I send at+wmfm?
the answer is
+WMFM: 0,2,1,1
+WMFM: 0,2,2,1
+WMFM: 0,2,3,0
+WMFM: 1,2,4,0
+WMFM: 1,2,4,1
Why there is no any values with +WMFM: 0,1,, ? Help me plz, if u can…


Did you issue AT+CMEE=1 to request the additional error codes…?


“Did you issue AT+CMEE=1 to request the additional error codes…?”
Thanks! Now the modem sends the answer - CME ROOR 3. Why this Operation not allowed?


maybe because UART2 is already active. This is indicated by +WMFM: 0,2,2,1. If the UART2 is not active the result should be +WMFM: 0,2,2,0.


The result is +WMFM: 0,2,2,1. But, when I send at+wmfm=0,0,2 the result is +CME ERROR: 3 why i can’t close UART2 if it’s already active?


There is something strange - when i send at+wopen=0, and after that i send at+wmfm=0,1,2 - it works, and at+wmfm=0,0,2 works too. It seems like this command don’t works when the OAT application started…
P.S. I do nothing with UART2 in my application…
Please help me to solve my problem…


Maybe UART2 use some GPIO — please take a look into the manual or data sheet of your module. If you use these ports in your application activation of the uart fails …


I have exactly the same problem. I have observed the following. Note that this used to work with firmware 6.63c but no longer works with R71b.

  1. After starting my application I can open and close UART 2 using AT+WMFM=0,1,2 and AT=WMFM=0,0,2
  2. However once I subscribe to the UART2 port - I can no longer use these commands either manually or in a program using the function

Why this is I haven’t a clue

And I agree with kban that if i stop the application then these commands can be issued.


Actually, that sounds like perfectly reasonable behaviour to me!

If your application has subscribed the UART, it is effectively “using” it - so I would expect that to prevent other commands from closing it, surely?

As a test, if your application unsubscribes the UART, can you then use those commands?


Therefore, it is not exactly the same problem, is it?

Unless there’s something that kban isn’t telling us…



I had this problem too. It can be solved by redownloading the wpb.dwl file.


Sorry I meant to say w.dwl file.