why the ttyUSB disappear,only cdc-wdm0 interface left

IoT Modules MC/EM Series
1

Dear support:

        I Used your three modules .MC7304,MC7330 ,and 7354 on linux system , but someday, in all the modules,  /dev/ttyUSB can not be found on linux system.  only one interface  /dev/cdc-wdm0 can be found ,SO I can not find any interface on windows 10 and linux ,neither AT command nor PPP call I can use  , can you give me easy way on how to  restore the default , the dev/ttyUSB interface can be found on linux system. thanks :frowning:
2

I downloaded the script from the webpage https://forum.sierrawireless.com/t/my-mc7710-cant-work-on-linux-after-plug-in-it-to-windows8/7986/1 ,but it didn;t wok.

3

Dear support:

         would you please give me some advice ？THANKS.
4

There are two possible reasons for this

  • Most likely your system has started to use the qmi_wwan driver which is present on your system rather than the GobiNet one. You can either remove the module from the system completely (I have issues with this) or black list the modem by adding the line ‘blacklist qmi_wwan’ to the /etc/modprobe.d/blacklist-modem.conf file.
  • Some how the USB composition of the device has changed, it should be set to mode 7, check it out with the below commands
    at!entercnd=“A710”
    at!udusbcomp?
    at!udusbcomp=? //This shows all of the possible modes it can be in.

Regards

Matt

5

Dear Matt:

         I have blacklist the qmi_wwan . but  when I reset the module . I can see that only CDC-WDM0 left ,there is no  any ttyUSB inferface that I can input any at command . 
         I want to restore the default setting (three ttyUSB interfaces). would you please tell me a easy way ,thanks? :slight_smile:
6

Firstly plug the device into a Windows machine (after having installed the drivers) and check to see if you can see the serial ports. If you can then the unit is setup correctly, if not it is in MBIM mode only and you need to check out https://forum.sierrawireless.com/viewtopic.php?f=117&t=8863&start=15#p37212.

Assuming the prots do come up I would STRONGLY recommend deleting every instance of the open source QMI interfaces from the system, I have seen instances recently where the unit was configured correctly and

You need to do the following

sudo modprobe -r qmi_wwan
rm /lib/modules/$kenel/drivers/usbserial/qcserial.ko

there is also going to be qmi_wwan.ko file around somewhere (may well be the same path as above) , you need to find it and delete it as well. After this reboot.

Install the GobiSerial and GobiNet devices then plug the unit in after that you should be able to see the /dev/ttyUSB’s and /dev/qcqmi interfaces.

Regards

Matt

7

Sorry missed you had done the instructions at https://forum.sierrawireless.com/viewtopic.php?f=117&t=8863&start=15#p37212. Plug it into a Windows machine and tell me what you see.

Regards

Matt