7 thoughts on “GT864 V2 AT&S DSR

  1. Hallo,


    I am testing GT864-PY V2 with  SW:10.00.003 HW:G1b


    I have a problem, module seems not to drive DSR serial PIN. 


    I have also checked if +CFUN was correct , but even if I change settings using AT&S I have nothing on the serial port. If I set AT&S2 during an incoming call I also have no change. I have set parameter to have DSR pin always ON but no change.


    I havent had this problem using previous version.


    Does anyone has an idea?


    Thank You 

    1. for AT&S2 setting DSR is normally LOW and it changes the status to HIGH when a DATA call is active (not ringing).  This has been tested on a 10.00.003 and it works.

      For the other settings:


      Default status for AT&S1, AT&S2 is LOW when not connected

      Default status for AT&S0 and AT&S3 is HIGH when ON and ready to receive commands.


      You should be able to see DSR status change between AT&S0 and AT&S1.

      1. Thank You,


        I have seen that problem is not related in AT commands.


        My problem is that on that module for default (GT864 version 2)  RS232 external port is completely off if it has nothing connected on the other side,


        My device has rs232 off when module makes connections so I had this problem. DSR becomes high when module finishes connection if at least a signal is already present on serial port.


        I solved the problem but is there an AT command that leaves rs232 always on (I keep module in state CFUN=1 so no power save mode)? 


        Thank You for attention



    1. Hallo Cosmin,


      I mean that if nothing is connected to 232 port no signal is present there.


      I should read positive voltage for logic 1 and negative voltage for logic 0 but if there are no signal connected on the port (I mean a signal from another device e.g. negative voltage of RX) I read all zero voltage from 232 modem. That is why I think that 232 driver is like off in this condition.


      In some way I solved however default behaviour in this condition is a bit different in respect of previous version. 


      Thank You for attention






        1. Hi Andrea,


          at now I solved jumping two pins on  my connectors.


          If there should be a software way let me know


          Thank You