# MC7455 /dev/cdc-wdm0 not identified as Modem **URL:** \ **Category:** MC/EM Series\ **Created:** [September 13, 2017, 7:19am UTC](https://forum.sierrawireless.com/t/mc7455-dev-cdc-wdm0-not-identified-as-modem/9488 "2017-09-13T07:19:05Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![evk1206](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/evk1206/32/3772_2.png) [@evk1206](https://forum.sierrawireless.com/u/evk1206)\ **Post date:** [September 13, 2017, 7:19am UTC](https://forum.sierrawireless.com/t/mc7455-dev-cdc-wdm0-not-identified-as-modem/9488/1 "2017-09-13T07:19:05Z")
Hi, For my project I am planning to use MC7455 module for LTE connection and also as GPS receiver. After powering up the system I could see that the device is getting attached. I am using Linux Kernel:4.9.39 and the build system is Yocto(Pyro). I am planning to use connman as the connection manager. Connman uses ofono for Modem related functionalities. The versions used are: Connman: 1.34 Ofono: 1.20. I tried to use the test scripts provided by Ofono. But after running the scripts, I am seeing that the modem is not getting identified. The log messages are as follows: root at cl-som-imx7:/usr/lib/ofono/test# ./list-modems root at cl-som-imx7:/usr/lib/ofono/test# root at cl-som-imx7:/usr/lib/ofono/test# ./enable-modem Traceback (most recent call last): File “./enable-modem”, line 14, in path = modems[0][0] IndexError: list index out of range I also tried using Modemmanager , modem manager also fails to attach the device. The log messages are as follows: cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Reading expected data format from: /sys/class/net/wwan0/qmi/raw\_ip cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Allocating new client ID… cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Registered ‘wda’ (version 1.16) client with ID ‘1’ cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Writing expected data format to: /sys/class/net/wwan0/qmi/raw\_ip cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Reading expected data format from: /sys/class/net/wwan0/qmi/raw\_ip cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Releasing ‘wda’ client with flags ‘release-cid’… cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Unregistered ‘wda’ client with ID ‘1’ cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Allocating new client ID… cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Registered ‘dms’ (version 1.14) client with ID ‘2’ cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Allocating new client ID… cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Registered ‘nas’ (version 1.25) client with ID ‘3’ cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Allocating new client ID… cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Registered ‘wms’ (version 1.10) client with ID ‘2’ cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Allocating new client ID… cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Registered ‘uim’ (version 1.45) client with ID ‘2’ cl-som-imx7 ModemManager[223]: (ttyUSB2): port attributes not fully set cl-som-imx7 ModemManager[223]: couldn’t load list of Own Numbers: ‘Couldn’t get MSISDN: QMI protocol error (16): ‘NotProvisioned’’ cl-som-imx7 ModemManager[223]: No valid PRI+MODEM pairs found. Assuming firmware unsupported. cl-som-imx7 ModemManager[223]: Modem: state changed (unknown -\> disabled) May I know what is the issue. I have flashed the latest MC7455 firmware. Manufacturer: Sierra Wireless, Incorporated Model: MC7455 Revision: SWI9X30C\_02.24.03.00 r6978 CARMD-EV-FRMWR2 2017/03/02 13:36:45 MEID: 35907206082918 IMEI: 359072060829187 IMEI SV: 9 FSN: LQ716600820410 +GCAP: +CGSM Regards, Vinoth ---
**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:** [September 13, 2017, 10:19am UTC](https://forum.sierrawireless.com/t/mc7455-dev-cdc-wdm0-not-identified-as-modem/9488/2 "2017-09-13T10:19:16Z")
> [@evk1206](#): > > also tried using Modemmanager , modem manager also fails to attach the device. The log messages are as follows: > > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Reading expected data format from: /sys/class/net/wwan0/qmi/raw\_ip > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Allocating new client ID… > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Registered ‘wda’ (version 1.16) client with ID ‘1’ > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Writing expected data format to: /sys/class/net/wwan0/qmi/raw\_ip > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Reading expected data format from: /sys/class/net/wwan0/qmi/raw\_ip > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Releasing ‘wda’ client with flags ‘release-cid’… > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Unregistered ‘wda’ client with ID ‘1’ > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Allocating new client ID… > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Registered ‘dms’ (version 1.14) client with ID ‘2’ > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Allocating new client ID… > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Registered ‘nas’ (version 1.25) client with ID ‘3’ > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Allocating new client ID… > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Registered ‘wms’ (version 1.10) client with ID ‘2’ > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Allocating new client ID… > cl-som-imx7 ModemManager[223]: [/dev/cdc-wdm0] Registered ‘uim’ (version 1.45) client with ID ‘2’ > cl-som-imx7 ModemManager[223]: (ttyUSB2): port attributes not fully set > cl-som-imx7 ModemManager[223]: couldn’t load list of Own Numbers: ‘Couldn’t get MSISDN: QMI protocol error (16): ‘NotProvisioned’’ > cl-som-imx7 ModemManager[223]: No valid PRI+MODEM pairs found. Assuming firmware unsupported. > cl-som-imx7 ModemManager[223]: Modem: state changed (unknown → disabled) This looks fine to me. What problem do you have? ---
**Author:** ![evk1206](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/evk1206/32/3772_2.png) [@evk1206](https://forum.sierrawireless.com/u/evk1206)\ **Post date:** [September 13, 2017, 10:40am UTC](https://forum.sierrawireless.com/t/mc7455-dev-cdc-wdm0-not-identified-as-modem/9488/3 "2017-09-13T10:40:46Z")
Hi, Normally I use ofono to connect the MODEM to internet. But the ofono is not able to identify any modems. With Modemmanager I saw some error messages, cl-som-imx7 ModemManager[223]: couldn’t load list of Own Numbers: ‘Couldn’t get MSISDN: QMI protocol error (16): ‘NotProvisioned’’ cl-som-imx7 ModemManager[223]: No valid PRI+MODEM pairs found. Assuming firmware unsupporte So I thought that Modemmanager is also not able to connect to the Module. I am seeing two different protocols :MBIM and QMI . I am confused by what should I use. I have worked previously with TELIT modems which uses QMI protocol . If I understood the technical specification, SIeraa supports both QMI and MBIM. I can change this by using the AT command " AT!USBCOMP " . The RMNET corresponds to QMI. Regards, Vinoth ---
**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:** [September 13, 2017, 10:48am UTC](https://forum.sierrawireless.com/t/mc7455-dev-cdc-wdm0-not-identified-as-modem/9488/4 "2017-09-13T10:48:41Z")
> [@evk1206](#): > > With Modemmanager I saw some error messages, > > cl-som-imx7 ModemManager[223]: couldn’t load list of Own Numbers: ‘Couldn’t get MSISDN: QMI protocol error (16): ‘NotProvisioned’’ > cl-som-imx7 ModemManager[223]: No valid PRI+MODEM pairs found. Assuming firmware unsupporte These are warnings, not errors.It just means that MM will list your number as ‘unknown’ and the firmware management interface will be unable. But I don’t see how that is a problem unless you were looking for those specific features.