Mc7455 low power mode. i need help

IoT Modules MC/EM Series
1

I just bought an mc7455 went to set it up and it wont work it is stuck in low power mode if any one knows how to fix it could you please let me know. i have tried flashing the firmware and have looked everywhere with no luck.

Recieve: ati
Recieve: Manufacturer: Sierra Wireless, Incorporated
Recieve: Model: MC7455
Recieve: Revision: SWI9X30C_02.33.03.00 r8209 CARMD-EV-FRMWR2 2019/08/28 20:59:30
Recieve: IMEI: 359072061513111
Recieve: IMEI SV: 20
Recieve: FSN: LQ911102710210
Recieve: +GCAP: +CGSM
Recieve: OK

Send:at!pcinfo?

Recieve: at!pcinfo?
Recieve: State: Low Power Mode
Recieve: LPM voters - Temp:0, Volt:0, User:0, W_DISABLE:0, IMSWITCH:1, BIOS:0, LWM2M:0, OMADM:0, FOTA:0
Recieve: LPM persistence - None
Recieve: OK

Send:At!priid?

Recieve: At!priid?
Recieve: PRI Part Number: Unknown
Recieve: Revision: Unknown
Recieve: Customer: Unknown
Recieve: Carrier PRI: None
Recieve: OK

Send:at!entercnd=“A710”

Recieve: at!entercnd=“A710”
Recieve: OK

Send:AT!PRIID?

Recieve: AT!PRIID?
Recieve: PRI Part Number: Unknown
Recieve: Revision: Unknown
Recieve: Customer: Unknown
Recieve: Carrier PRI: None
Recieve: OK

Send:at!gobiimpref?

Recieve: at!gobiimpref?
Recieve: !GOBIIMPREF:
Recieve: preferred fw version: 02.33.03.00
Recieve: preferred carrier name: GENERIC
Recieve: preferred config name: GENERIC_002.072_000
Recieve: preferred subpri index: 000
Recieve: current fw version: 02.33.03.00
Recieve: current carrier name:
Recieve: current config name:
Recieve: current subpri index: 000
Recieve: carrier name mismatch
Recieve: config name mismatch
Recieve: OK

2

Not sure if you can fix it by AT!IMPREF=preference
You can give a try.

3

i have tried that. i did how ever last night find an at command to keep the sim card powered in low power mode about to give it a try but id still like to have it fully operational tho for as expensive as these cards are i may end up returning it and getting a new one.

4

Then what is the result

5

it was a no go still wouldnt connect.

6

What is at!impref?

At!image?

7

sorry i already repackaged it and sending it back so they can send me a new on i stayed up two nights in a row till 3 am researching others that were having the same problem and tried everthing the told others to try and like the others it didnt work. the fw didnt match the pri. thats what everyone kept saying but no one had a fix for it.

8

Some post necromancy here.

For whoever might find that the modem cannot connect to carrier, ie sending SMS gives error 350, modem stays in “low power mode” (check with qmicli -d /dev/cdc-wdm0 --dms-get-operating-mode), or has the following errors in dmesg:

[  479.928358] qmi_wwan 2-2:1.8: wdm_int_callback - 0 bytes
[  479.958698] qmi_wwan 2-2:1.8: nonzero urb status received: -71
[  479.960126] qmi_wwan 2-2:1.8: wdm_int_callback - 0 bytes
[  479.990724] qmi_wwan 2-2:1.8: nonzero urb status received: -71

Here’s a quick test and maybe a quick resolution:

Check whether the requested firmware and carrier match the installed ones.
Using picocom -b 19200 /dev/ttyUSB2 (or whatever ttyUSB your modem is bound to):

AT&F
OK
AT!IMPREF?
!IMPREF:
 preferred fw version:    02.38.00.00
 preferred carrier name:  Generic
 preferred config name:   Generic_002.082_000
 preferred subpri index:  000
 current fw version:      02.38.00.00
 current carrier name:    GENERIC
 current config name:     GENERIC_002.017_000
 current subpri index:    000

 carrier name mismatch
 config name mismatch

OK

In my case, I mad a firmware update with carrier name “Generic” instead of “GENERIC”.
Updating that value fixed my problem, modem could connect to internet.

Fixed with:

qmicli -d /dev/cdc-wdm0 -p --dms-set-firmware-preference="firmware-version=02.38.00.00,config-version=002.082_000,carrier=GENERIC"

After that, miraculously, the current config name of the carrier updated to the new one:

AT!IMPREF?
!IMPREF:
 preferred fw version:    02.38.00.00
 preferred carrier name:  GENERIC
 preferred config name:   GENERIC_002.082_000
 preferred subpri index:  000
 current fw version:      02.38.00.00
 current carrier name:    GENERIC
 current config name:     GENERIC_002.082_000
 current subpri index:    000

OK
9

Another way is to redownload the PRI file:


owner@ubuntu:~/QMI/MBPL/MBPL_SDK_R25_ENG3-lite.bin/SampleApps/lite-fw-download$ sudo ./bin/fwdwl-litehostx86_64 -m 3 -d /dev/ttyUSB0 -p /dev/cdc-wdm0 -t 2 -f /home/owner/Desktop/MC7455_FW/9999999_9904609_SWI9X30C_02.38.00.00_00_GENERIC_002.082_000/  -w SWI9X30C_02.38.00.00.cwe  -n SWI9X30C_02.38.00.00_GENERIC_002.082_000.nvu
Application version: 1.0.2111.0
INFO: QDL Port  :  /dev/ttyUSB0
INFO: Device Path: /dev/cdc-wdm0
INFO: FW  Path  :  /home/owner/Desktop/MC7455_FW/9999999_9904609_SWI9X30C_02.38.00.00_00_GENERIC_002.082_000/
Target image Info:
Carrier    :GENERIC
FW Version :02.38.00.00
Model ID   :SWI9X30C
Package ID :000
PRI Version:002.082
SKU        :9999999
Switching device into download mode ...
No need to download any images.  Device will reboot for image switching.
Waiting for modem to disconnect from the host ...
Modem disconnected from host.
Waiting for modem to come up in ONLINE mode ...
Modem is now in ONLINE mode ... 
FW update status: Successful
FW info from modem:
Model ID            : EM7455
FW Version          : SWI9X30C_02.38.00.00
Carrier Name        : GENERIC
Carrier PRI Revision: 002.082_000
Firmware Download Process completed
Exiting Application!!!
owner@ubuntu:~/QMI/MBPL/MBPL_SDK_R25_ENG3-lite.bin/SampleApps/lite-fw-download$