# MC7710 with PID 9205, doesn't receive AT commands **URL:** \ **Category:** MC/EM Series\ **Created:** [July 8, 2021, 7:03am UTC](https://forum.sierrawireless.com/t/mc7710-with-pid-9205-doesnt-receive-at-commands/24179 "2021-07-08T07:03:49Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![tuxor1337](https://avatars.discourse-cdn.com/v4/letter/t/ed8c4c/32.png) [@tuxor1337](https://forum.sierrawireless.com/u/tuxor1337)\ **Post date:** [July 8, 2021, 7:03am UTC](https://forum.sierrawireless.com/t/mc7710-with-pid-9205-doesnt-receive-at-commands/24179/1 "2021-07-08T07:03:49Z")
Hi everyone, I bought a used MC7710 WWAN module and it shows up in Linux (kernel 5.12.13) as PID 9205: ```auto # lsusb Bus 002 Device 002: ID 1199:9205 Sierra Wireless, Inc. MC7710 ... ``` Consequently, no linux driver will connect to it. However, I was able to force `qcserial` and `qmi_wwan` to recognize the module, using the following commands: ```auto # modprobe qmi_wwan # echo "1199 9205" | sudo tee /sys/bus/usb/drivers/qmi_wwan/new_id 1199 9205 # modprobe qcserial # echo "1199 9205" | sudo tee /sys/bus/usb-serial/drivers/qcserial/new_id 1199 9205 ``` After that, some devices are exposed, but strangely enough, only a single serial interface: ```auto # lsusb -tv ... /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/6p, 480M ID 1d6b:0002 Linux Foundation 2.0 root hub |__ Port 4: Dev 2, If 0, Class=Vendor Specific Class, Driver=, 480M ID 1199:9205 Sierra Wireless, Inc. |__ Port 4: Dev 2, If 2, Class=Vendor Specific Class, Driver=qcserial, 480M ID 1199:9205 Sierra Wireless, Inc. |__ Port 4: Dev 2, If 3, Class=Vendor Specific Class, Driver=qmi_wwan, 480M ID 1199:9205 Sierra Wireless, Inc. |__ Port 4: Dev 2, If 8, Class=Vendor Specific Class, Driver=qmi_wwan, 480M ID 1199:9205 Sierra Wireless, Inc. ... ``` Using `screen /dev/ttyUSB0` and `minicom -D /dev/ttyUSB0`, I tried to send AT commands to the module, but there is no reaction whatsoever. However, I was able to send QMI commands using `qmicli` and decided to install the latest QMI firmware version using `qmi-firmware-update --update -d 1199:9205 9999999_9999999_9200_03.05.29.03_00_generic_000.000_001_SPKG_MC.cwe`. Indeed, this shows up nicely with `qmicli`, but doesn’t change the behavior at all: ```auto # qmicli -d /dev/cdc-wdm1 --dms-swi-get-current-firmware [/dev/cdc-wdm1] Successfully retrieved current firmware: Model: MC7710 Boot version: SWI9200X_03.05.29.03bt r6485 CNSHZ-ED-XP0031 2014/12/02 17:33:08 AMSS version: SWI9200X_03.05.29.03ap r6485 CNSHZ-ED-XP0031 2014/12/02 17:53:15 SKU ID: unknown Package ID: unknown Carrier ID: 0 Config version: unknown ``` Furthermore, I can change the USB composition using `--dms-swi-set-usb-composition=[#]`, but none of the available compositions enables me to send AT commands: ```auto # qmicli -d /dev/cdc-wdm1 --dms-swi-get-usb-composition [/dev/cdc-wdm1] Successfully retrieved USB compositions: [*] USB composition 6: DM, NMEA, AT, QMI USB composition 7: DM, NMEA, AT, RMNET1, RMNET2, RMNET3 USB composition 8: DM, NMEA, AT, MBIM USB composition 9: MBIM USB composition 10: NMEA, MBIM USB composition 11: DM, MBIM USB composition 12: DM, NMEA, MBIM USB composition 13: Dual configuration: USB composition 6 and USB composition 8 USB composition 14: Dual configuration: USB composition 6 and USB composition 9 USB composition 15: Dual configuration: USB composition 6 and USB composition 10 USB composition 16: Dual configuration: USB composition 6 and USB composition 11 USB composition 17: Dual configuration: USB composition 6 and USB composition 12 USB composition 18: Dual configuration: USB composition 7 and USB composition 8 USB composition 19: Dual configuration: USB composition 7 and USB composition 9 USB composition 20: Dual configuration: USB composition 7 and USB composition 10 USB composition 21: Dual configuration: USB composition 7 and USB composition 11 USB composition 22: Dual configuration: USB composition 7 and USB composition 12 ``` Is there anything I can do to get the module working? ---
**Author:** ![dl5162](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/dl5162/32/2169_2.png) [@dl5162](https://forum.sierrawireless.com/u/dl5162)\ **Post date:** [July 8, 2021, 1:02pm UTC](https://forum.sierrawireless.com/t/mc7710-with-pid-9205-doesnt-receive-at-commands/24179/2 "2021-07-08T13:02:00Z")
> [@tuxor1337](#): > > ```auto > # modprobe qmi_wwan > # echo "1199 9205" | sudo tee /sys/bus/usb/drivers/qmi_wwan/new_id > 1199 9205 > # modprobe qcserial > # echo "1199 9205" | sudo tee /sys/bus/usb-serial/drivers/qcserial/new_id > 1199 9205 > > ``` Try reversing that. Your problem is that qmi\_wwan binds to every interface which could possibly be RMNET/QMI. It doesn’t know which one is the correct one when you .use new\_id. So it blocks qcserial from binding to interface #3, which is the AT command interface. Once you have AT command access you should probably change to a supported PID, unless there is a specific reason this module is using 9205. ---
**Author:** ![tuxor1337](https://avatars.discourse-cdn.com/v4/letter/t/ed8c4c/32.png) [@tuxor1337](https://forum.sierrawireless.com/u/tuxor1337)\ **Post date:** [July 8, 2021, 2:31pm UTC](https://forum.sierrawireless.com/t/mc7710-with-pid-9205-doesnt-receive-at-commands/24179/3 "2021-07-08T14:31:08Z")
Thanks for the quick reply! In fact, reversing the two commands exposed three ttyUSB devices, one of which received AT commands. Using that, I was able to change the PID (to 68a2, i.e. QMI mode), following the instructions from here: [Sierra Wireless switch QMI DPI modes · GitHub](https://gist.github.com/mmv-ru/1a52c10a4d5577a5ed30) Now, with the correct PID, ModemManager automatically recognizes the module and is actually able to establish a mobile connection. However, I found out that the SIM card I wanted to use first has actually been deactivated by the carrier months ago. Good to know… The second SIM card I tried worked fine.