FTP timeout…

10 thoughts on “FTP timeout…

  1. Hi.
    I have some problem with AT command .

    My application use ATD command and I want use AT#FTP… command.

    If is request then call to any number up to 3sec. But if use AT#FTP command then timeout is up to 50sec and on this time can receive request for call to number but I still wait for answer from AT#FTP… command.
    is possible to terminate AT#FTP… and start call immediately???

    Exist any solution for this in one serial port???



    1. Hi Sevc, you’ll have to use CMUX for such things. Alternatively, some FTP commands have versions which work in command mode, and you can set a short timeout for some actions, opening control or traffic channel..

      1. Hi.

        I don’t want use CMUX. it’s complicated use CMUX. why don’t exist easy solution for controll virtual serial port or some special char to cancel the previous command, or don’t wait for a response .

        ehm… FTP command .
        can you write here some solution how to use this at command with short timeout???
        If I want open connection to FTP server or close, open file for read , open file for write …. in all this command some time Imust wait more then 10sec. is possible to change this time?




        1. A designer must make use of a platform in creative ways, in almost all cases the software application must be shaped to fit a specific hardware; one cannot implement the software making abstraction of what capabilities are offered, so, as I said before, maybe you should be little more flexible in your design.


          Set a short convenient timeout for channel opening, then use command mode FTP get in command mode so you have the AT console at your discretion. For FTP put is no problem, simply close connection with +++ if you need to.

          However, with short opening timeouts, you have chances to not be able to connect reliable in many network conditions.


        2. Hi. I’m search some information about CMUX and find document IPEasy and MULTISOCKET . I ‘m read it and don’t find information how to use it with FTP.

          can you help with this . write more about this solution.

          I want connect to FTP and keep it live. and if need then send special file to FTP but if is request for call to any number then must  stop all that has to do with FTP commands and begin to communicate the call initiation.



  2. There is a CMUX User Guide document in Download Zone, Linux driver sources are available if your host can cope with their complexity.


    Multisocket cannot be used as they are dealing only with socket connections.


    FTP commands do not keep the AT console busy, for example AT#FTPOPEN opens connection and returns after, so if you set short timeout you’ll have quick access to AT commands. For the commands that keep the line busy, like file transfers, I gave a solution above.


    1. FTP is too socket connection.

      IF don’t use FTP at command and use socket command and my self program make FTP client then I can use multisocket.  

      But how to set minimal timeout for AT#FTP command???

      example pls. 

      time critical is for me only Open connection to FTPserver and then save new file on the server. short size .
      I prefer so if open FTP connection then don’t close it. still hold open connection.

      only if check so connection lost then reopen. every one min I send to FTP server nop information for keep it alive. and only if need then send file to FTP.


      I don’t have access to download zone, but CMUX is too complicated.

      may can make other easy solution like CMUX but more easy.

      why is not possible to change serial port mux with external hardware pin or special char??? it’s will good if can use any gipio to switch serial port mux from port 1 to 2.3.GPS.

      if someone use external MCU than have lot free pin and don’t use GPIO. and then are this GPIO free and can use to switch internal mux. 

      1. I suppose you have AT Commands Reference Guide, is free download from each product page, see AT#FTPTO command. FTP protocol references are available in many places, see there how it works on 2 socket channels, control and traffic, passive and active modes etc. – I am sure you will not want to implement it yourself, is much simpler to find round easier way around the obstacles.


        Look now another nice idea: make a small Python application which will only do a simple thing: dispatch (bridge) your normal AT commands to one MDM interface and  the FTP jobs to the second MDM, this way you’ll have them running in parallel.


        In any case, don’t forget: modules are class B so GPRS traffic is suspended during GSM jobs (call, SMS).



          Yes , I too have idea to make small PHYTON scrypt to work only with FTP and all other use for standard command. but I don’t know if my now hardware setting support run phyton scrypt parallel with my application. Priority are for me voice and SMS, but I don’t know when is comming request for SMS or voice but I know when I want use FTP connection. but both FTP and socket connection can have big timeout. Multisocket is good way but must make more test and compare what is good way.

          it’s will good if  telit technical support published source code for CMUX mplementation in C or other language.

          but for this time I use FTP only for upgrade my firmware in my MCU and work good.

          but if I’m on bootloader mode then don’t want call or send SMS. just after download and all is OK then inform user with SMS of progress download.



          1. it’s will good if  telit technical support published source code for CMUX mplementation in C or other language.

            There is a CMUX User Guide document in Download Zone, Linux driver sources are available if your host can cope with their complexity.


            Linux CMUX driver I mean, and they are in C. As already said, don’t expect to be easy to port on a small microcontroller, maybe is easier to write a simpler implementation from scratch.