MC7421 stuck on the boot

IoT Modules MC/EM Series
1

Hello,
some of our remote modules often stuck on the boot (only ttyUSB0 was shown in /dev ), and only firmware upgrade resolve the problem, is there any command that I may run to disable this issue
fyi I use MBPL driver and the SWI9X50C_01.14.13.00 002.048_000 as firmware

2

Could be some flash corruption due to ungraceful power down

3

So how I can fix this problem

4

You need to follow the power down sequence in PTS

Or you can prepare a backup firmware in host platform to download to module which kept in download mode

5

Unfortunately the router doesn’t have enough memeory to store MC7421 firmware (SWI9X50C_01.14.13.00.cwe size=74000KB) and we can’t now change the 500 mother board to respect MC721’s power down sequence,(routers already installed )
is there any other solution

6

How many images have been installed in at!image?

7

here the output

root@VSAV_429:~# atexecute ttyUSB2 “at!priid?”
at!priid?
PRI Part Number: 9909877
Revision: 002.004
Customer: Generic-M2M

Carrier PRI: 9999999_9907259_SWI9X50C_01.14.13.00_00_GENERIC_002.048_000

OK
root@VSAV_429:~# atexecute ttyUSB2 “at!image?”
at!image?
TYPE SLOT STATUS LRU FAILURES UNIQUE_ID BUILD_ID
FW 1 GOOD 1 0 0 ?? 01.14.03.00?
FW 2 GOOD 2 0 0 ?? 01.14.13.00?
FW 3 EMPTY 0 0 0
FW 4 EMPTY 0 0 0
Max FW images: 4
Active FW image is at slot 2

TYPE SLOT STATUS LRU FAILURES UNIQUE_ID BUILD_ID
PRI FF GOOD 0 0 0 002.048_000 01.14.13.00_GENERIC
Max PRI images: 50

OK
root@VSAV_429:~#

onother router
root@VSAV_29:~# atexecute ttyUSB2 “at!image?”
at!image?
TYPE SLOT STATUS LRU FAILURES UNIQUE_ID BUILD_ID
FW 1 GOOD 1 0 0 ?? 01.14.03.00?
FW 2 EMPTY 0 0 0
FW 3 EMPTY 0 0 0
FW 4 EMPTY 0 0 0
Max FW images: 4
Active FW image is at slot 1

TYPE SLOT STATUS LRU FAILURES UNIQUE_ID BUILD_ID
PRI FF GOOD 0 0 0 002.036_010 01.14.03.00_GENERIC
Max PRI images: 50

OK

another question how to implement the process of required powerdown sequence described in the MC7421 datasheet page 49 to avoid file system corruption in other word how to run the process if some one unplug the power supply cable
if we admit that the board will lose power instantly if there is no power

8

you should have some backup battery in order to comply with the power down sequence

BTW, if you download one more FW+PRI with other carrier (e.g. KT), will it switch to another FW when problem happens?

9

BTW, if you download one more FW+PRI with other carrier (e.g. KT), will it switch to another FW when problem happens?
I didn’t understand how to do it exactly, as I know i should always set the preferred firmware
could you send an example please

10
  1. download the KT exe to it
  2. AT!IMAGE? should show two FW
  3. now switch to GENERIC PRI by AT!IMPREF.

I just wonder if flash corruption happens after ungraceful power down, will it switch to KT FW+PRI?

11

I just wonder if flash corruption happens after ungraceful power down, will it switch to KT FW+PRI?
where we can get the answer

12

you can do the test and see what happens

13

Is there any trick or command to corrupt the firmware to speed up the test in the LAB and check if this methode resolves the problem

14

no, i don’t have
maybe you can do some power cycle stress test with power supply