Repeated AT+CMGL Command Over CMUX

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5 thoughts on “Repeated AT+CMGL Command Over CMUX”

  1. I’m using a HE910 with firmware 12.00.003 

     

    I’m repeatedly issuing an AT+CMGL command over a CMUX virtual port about 15 to 30 seconds apart.  After about 15 to 30 minutes, the CMUX virtual port that I am issuing the commands over will stop working entirely.  Other CMUX virtual ports will continue to operate as expected.  

    I have tried running other commands (ATZ, AT+CSQ, AT+CREG?) with that frequency and they don’t lock up the virtual port.  AT+CMGL appears to be the problem.

     

    Any ideas as to what would cause this? 

     

    Thanks! 

    1. Hi Jeff,

       

      I think I need more details on your set up , since I open two virtual channel and send AT+CMGL on ch 1 every 15 secs for more then 30 min but I can’t see any issue.

      BR

      Luca

      1. Luca,

        I’m applying power to the HE910, then after the power on sequence, I wait for both pwrmon and reset pin to go high

         

        Next I run the following commands:

        AT+IPR=115200

        AT#ENS=1

        AT#SELINT=2

        AT+CMUX=?

        ATE0V1&K3&D2

        AT&S0

        AT&W0&P0

        AT#RXDIV=0,3

        AT+CMUXMODE=0

        AT+CPUMODE=3

        AT+CGMM

        AT+CMUX=0

         

        After that I send SABM to DLCI 0, 1, 2, and 3

        On virtual port 1 I loop the following about every 15 seconds:

        AT+CREG?

        AT+CSQ

        AT+CGML 

         

        On virtual port 2, I make a socket connection

        On virtual port 3, I receive GPS data about every 5 seconds

         

        I noticed that if I wait about 1 minute between  AT+CGML commands, the problem won’t happen.  Could the frequency of commands be the problem?  I am also testing with very poor cell reception.  I’m not sure if that has anything to do with it.

         

        Thanks!

        1. Hi Jeff,

           

          CMGL  need a SIM card reading and you are performing also a lot of

          other stuff on module. It can be the reply will be delayed a lot .. 

          I believe in yourenvironment try to read the SMS every 15 secs cna harm the system