MC7455 ReV B Reset after SIMToolKit REFRESH takes long time

IoT Modules MC/EM Series
1

Hello,
I have two modems MC7455, one is labeled as REV A and the other as REV B.

With REV B, I observed that when the UICC request for a SIMToolKit REFRESH command (80 12 00 00 0B D0 09 81 03 01 01 04 82 02 81 82), the modem takes around 10 seconds to reset the UICC. The measurement has been taken with Comprion Minimove, so there are quite accurate.

REV A is working as expected and Reset is triggered right away (just few milliseconds) after the REFRESH from the SIM

why REV B takes so long to reset of the UICC?

2

Hi @jordi.monter,

Welcome to our community!

  1. Are both MC7455 modules running the same firmware? Please provide the Serial numbers for both modules.
  2. How did you perform the UICC reset? Did you do it with an AT command? If so, which AT command did you use?
  3. If you used AT command, please provide log files with timestamps for both modules to me.

Thanks,

3

Hello @jerdung ,
Thank you very much for your quick reply and your warm welcome
For the modules information, is there any command I can use to retrieve SN and Firmware version? I will run them in order to provide the requested information.

In regards of the UICC Reset, let me provide a little bit of context. This is an UICC with GSMA SGP.22 eSIM capabilities. We have an application that runs AT commands to perform eSIM operations (enable/disable/delete eSIM profiles). As a result of the commands the UICC issues a REFRESH proactive command in the response and the modem shall execute the Reset. However, everything happens in the background between the modem and the eUICC and the response is not sent back to the application. Therefore we can only observe the commands using a communication spy tool such as Comprion.
Find below a snipped of the traces (with timestamps measured in etu) took with the Comprion tool. In REV B logs, our application is trying to get the notifications via ‘BF2B’ command but it received SW ‘6985’ error because reset hasn’t been completed:
REVISION A
APDU > Header [CLA INS P1 P2] 81 E2 91 00 352.63 etu STORE DATA

Incoming data BF 31 11 A0 0C 5A 0A 98 00 00 00 00 00 00 00 30
F7 81 01 FF
< Outgoing data BF 31 03 80 01 00 35.00 etu
< Return code [SW1 SW2] 91 0B
APDU > Header [CLA INS P1 P2] 80 12 00 00 1037.75 etu FETCH
< Outgoing data D0 09 81 03 01 01 04 82 02 81 82 477.50 etu
< Return code [SW1 SW2] 90 00
APDU > Header [CLA INS P1 P2] 80 F2 02 0C 285.13 etu STATUS
< Return code [SW1 SW2] 90 00 1190.00 etu
Warm reset Event Reset card interface

REVISION B
APDU > Header [CLA INS P1 P2] 81 E2 91 00 377.75 etu STORE DATA

Incoming data BF 31 11 A0 0C 5A 0A 98 00 00 00 00 00 00 00 30
F7 81 01 FF
< Outgoing data BF 31 03 80 01 00 35.00 etu
< Return code [SW1 SW2] 91 0B
APDU > Header [CLA INS P1 P2] 80 12 00 00 790.75 etu FETCH
< Outgoing data D0 09 81 03 01 01 04 82 02 81 82 477.75 etu
< Return code [SW1 SW2] 90 00
APDU > Header [CLA INS P1 P2] 81 E2 91 00 289.25 etu STORE DATA
Incoming data BF 2B 00
< Return code [SW1 SW2] 69 85 5807.25 etu
APDU > Header [CLA INS P1 P2] 00 70 80 01 378.75 etu MANAGE CHANNEL
< Return code [SW1 SW2] 90 00 668.75 etu
APDU > Header [CLA INS P1 P2] 00 70 00 00 378.75 etu MANAGE CHANNEL
< Outgoing data 01 736.50 etu
< Return code [SW1 SW2] 90 00
APDU > Header [CLA INS P1 P2] 81 AA 00 00 312.50 etu TERMINAL CAPABILITY
Incoming data A9 03 83 01 07
< Return code [SW1 SW2] 90 00 1355.25 etu
APDU > Header [CLA INS P1 P2] 01 A4 04 00 377.00 etu SELECT
Incoming data A0 00 00 05 59 10 10 FF FF FF FF 89 00 00 01 00
< Outgoing data 6F 1F 84 10 A0 00 00 05 59 10 10 FF FF FF FF 89 34.88 etu
00 00 01 00 A5 04 9F 65 01 FF E0 05 82 03 02 04
00
< Return code [SW1 SW2] 90 00
APDU > Header [CLA INS P1 P2] 81 E2 91 00 314.00 etu STORE DATA
Incoming data BF 2B 00
< Return code [SW1 SW2] 69 85 2289.13 etu
APDU > Header [CLA INS P1 P2] 00 70 80 01 379.63 etu MANAGE CHANNEL
< Return code [SW1 SW2] 90 00 669.38 etu
APDU > Header [CLA INS P1 P2] 00 70 00 00 313.50 etu MANAGE CHANNEL
< Outgoing data 01 788.25 etu
< Return code [SW1 SW2] 90 00
APDU > Header [CLA INS P1 P2] 81 AA 00 00 375.13 etu TERMINAL CAPABILITY
Incoming data A9 03 83 01 07
< Return code [SW1 SW2] 90 00 1389.75 etu
APDU > Header [CLA INS P1 P2] 01 A4 04 00 376.63 etu SELECT
Incoming data A0 00 00 05 59 10 10 FF FF FF FF 89 00 00 01 00
< Outgoing data 6F 1F 84 10 A0 00 00 05 59 10 10 FF FF FF FF 89 35.00 etu
00 00 01 00 A5 04 9F 65 01 FF E0 05 82 03 02 04
00
< Return code [SW1 SW2] 90 00
APDU > Header [CLA INS P1 P2] 81 E2 91 00 376.88 etu STORE DATA
Incoming data BF 30 03 80 01 04
< Return code [SW1 SW2] 69 85 2288.63 etu
APDU > Header [CLA INS P1 P2] 00 70 80 01 381.13 etu MANAGE CHANNEL
< Return code [SW1 SW2] 90 00 671.00 etu
APDU > Header [CLA INS P1 P2] 00 A4 08 04 301.00 etu SELECT
Incoming data 7F FF 6F 5B
< Outgoing data 62 1C 82 02 41 21 83 02 6F 5B A5 03 C0 01 80 8A 34.88 etu
01 05 8B 03 6F 06 07 80 02 00 06 88 01 78
< Return code [SW1 SW2] 90 00
APDU > Header [CLA INS P1 P2] 00 D6 00 00 368.38 etu UPDATE BINARY
Incoming data 00 00 00 00 00 00
< Return code [SW1 SW2] 90 00 1860.50 etu
APDU > Header [CLA INS P1 P2] 80 F2 02 0C 294.63 etu STATUS
< Return code [SW1 SW2] 90 00 1226.25 etu
Warm reset Event Reset card interface

Thank you!!!

4

Hi @jordi.monter,

Assuming you are using the MC7455 on Windows, please install the driver for the MC7455 at the following link: https://source.sierrawireless.com/resources/airprime/software/airprime-em_mc-series-windows-drivers-qmi-build-latest-release/#sthash.uvct2jA2.dpbs

When you connect the module to the computer, an AT port will appear in the Modems section of the Device Manager. You can use Putty to enter AT commands.

Please enter the following commands to retrieve the Serial number and Firmware version:

ATI9
AT!IMPREF?

Afterward, kindly share the AT command log file for the UICC reset process with me.

Thanks,

5

Hi @jerdung,

Thank you for the instructions. Actually we are using both Windows and Raspberry Pi (same result is obtained not matters the OS). Below is the Firmware version and SN:

REVISION A

ATI9
Manufacturer: Sierra Wireless, Incorporated
Model: MC7455
Revision: SWI9X30C_02.30.01.01 r7792 CARMD-EV-FRMWR2 2018/07/13 02:24:52
MEID: 35907206186565
IMEI: 359072061865651
IMEI SV: 16
FSN: LQ805574390210

AT!IMPREF?
AT!IMPREF?
!IMPREF:
preferred fw version: 02.30.01.01
preferred carrier name: GENERIC
preferred config name: GENERIC_002.045_001
current fw version: 02.30.01.01
current carrier name: GENERIC
current config name: GENERIC_002.045_001

REVISION B

ATI9

Manufacturer: Sierra Wireless, Incorporated
Model: MC7455
Revision: SWI9X30C_02.24.05.06 r7040 CARMD-EV-FRMWR2 2017/05/19 06:23:09
MEID: 35907206391511
IMEI: 359072063915116
IMEI SV: 12
FSN: LQ850405900210

AT!IMPREF?
!IMPREF:
preferred fw version: 02.24.05.06
preferred carrier name: GENERIC
preferred config name: GENERIC_002.026_000
current fw version: 02.24.05.06
current carrier name: GENERIC
current config name: GENERIC_002.026_000

I’ve seen REV B firmware version is older than REV A

6

Hi @jerdung,

And below the AT commands we sent over both modems:

** REVISION A **

AT+CMEE=?
+CMEE: (0,1,2)
OK
AT+CMEE=2
OK
AT+CSIM=10,“0070000001”
+CSIM: 6,“019000”
OK
AT+CSIM=20,“81AA000005A903830107”
+CSIM: 4,“9000”
OK
AT+CSIM=44,“01A4040010A0000005591010FFFFFFFF890000010000”
+CSIM: 4,“6121”
OK
AT+CSIM=10,“01C0000021”
+CSIM: 70,“6F1F8410A0000005591010FFFFFFFF8900000100A5049F6501FFE00582030204009000”
OK
AT+CSIM=40,“BF3111A00C5A0A980000000000000030F78101FF”
+CSIM: 4,“9000”
OK
AT+CSIM=18,“81E2910003BF2B0000”
+CSIM: 4,“6881”
OK
AT+CSIM=10,“0070800100”
+CSIM: 4,“6200”
OK
AT+CMEE=?
+CMEE: (0,1,2)
OK
AT+CMEE=2
AT+CSIM=10,“0070000001”
+CSIM: 6,“019000”
OK
AT+CSIM=20,“81AA000005A903830107”
+CSIM: 4,“9000”
OK
AT+CSIM=44,“01A4040010A0000005591010FFFFFFFF890000010000”
+CSIM: 4,“6121”
OK
AT+CSIM=10,“01C0000021”
+CSIM: 70,“6F1F8410A0000005591010FFFFFFFF8900000100A5049F6501FFE00582030204009000”
OK
AT+CSIM=18,“81E2910003BF2B0000”
+CSIM: 4,“6100”
OK

As you can see above, retrieve Notifications command (Tag BF2B) failed with SW 6881 and Close logical channel failed with SW 6200, because the RESET has been executed by the modem in case of REV A (you can see the REFRESH command executed in my previous log extracted from Comprion tool).

** REVISION B **

AT+CMEE=?
+CMEE: (0,1,2)
OK
AT+CMEE=2
OK
AT+CSIM=10,“0070000001”
+CSIM: 6,“019000”
OK
AT+CSIM=20,“81AA000005A903830107”
+CSIM: 4,“9000”
OK
AT+CSIM=44,“01A4040010A0000005591010FFFFFFFF890000010000”
+CSIM: 4,“6121”
OK
AT+CSIM=10,“01C0000021”
+CSIM: 70,“6F1F8410A0000005591010FFFFFFFF8900000100A5049F6501FFE00582030204009000”
OK
AT+CSIM=40,“BF3111A00C5A0A980000000000000030F78101FF”
+CSIM: 4,“9000”
OK
AT+CSIM=18,“81E2910003BF2B0000”
+CSIM: 4,“6985”
OK
AT+CSIM=10,“0070800100”
+CSIM: 4,“9000”
OK
AT+CMEE=?
+CMEE: (0,1,2)
OK
AT+CMEE=2
AT+CSIM=10,“0070000001”
+CSIM: 6,“019000”
OK
AT+CSIM=20,“81AA000005A903830107”
+CSIM: 4,“9000”
OK
AT+CSIM=44,“01A4040010A0000005591010FFFFFFFF890000010000”
+CSIM: 4,“6121”
OK
AT+CSIM=10,“01C0000021”
+CSIM: 70,“6F1F8410A0000005591010FFFFFFFF8900000100A5049F6501FFE00582030204009000”
OK
AT+CSIM=18,“81E2910003BF2B0000”
+CSIM: 4,“6985”
OK
AT+CSIM=10,“0070800100”
+CSIM: 4,“9000”
OK
AT+CMEE=?
+CMEE: (0,1,2)
OK
AT+CMEE=2
AT+CSIM=10,“0070000001”
+CSIM: 6,“019000”
OK
AT+CSIM=20,“81AA000005A903830107”
+CSIM: 4,“9000”
OK
AT+CSIM=44,“01A4040010A0000005591010FFFFFFFF890000010000”
+CSIM: 4,“6121”
OK
AT+CSIM=10,“01C0000021”
+CSIM: 70,“6F1F8410A0000005591010FFFFFFFF8900000100A5049F6501FFE00582030204009000”
OK
AT+CSIM=18,“81E2910003BF2B0000”
+CSIM: 4,“6985”
OK
AT+CSIM=10,“0070800100”
+CSIM: 4,“9000”
OK
As you can see above, retrieve Notifications command (Tag BF2B) failed with SW 6985, because in this case the RESET was not executed by the modem after ENABLE PROFILE command in case of REV B (you can see the exactly sequence executed by the modem in my previous log extracted from Comprion tool).

7

Hi @jordi.monter,

According to your description, when using the APDU tool, the MC7455 RevA works well as expected. However, when using AT commands, there seems to be an issue, is that correct?

Additionally, the two MC7455 modules have different firmware versions, and the MC7455 RevA works as expected. Therefore, consider updating the firmware of the MC7455 RevB to match the firmware version of the MC7455 RevA to see if the issue persists.

Thanks,

8

Hi @jerdung ,

That’s correct. I was looking for release notes were I can see if there is anything related with the issue I described in any of the firmware updates, but I didn’t find anything. Therefore I am not sure if this is related to the firmware version or maybe some configuration of the modem.
What is the recommended version of the firmware?

BR,
Jordi

9

Hi @jordi.monter,

Could you please upload the firmware for MC7455 revB, matching the firmware of MC7455 revA (GENERIC SWI9X30C_02.30.01.0) to see if the issue still occurs?

Kindly refer to the firmware at the following link: https://source.sierrawireless.com/resources/airprime/minicard/74xx/em_mc74xx-approved-fw-packages/#sthash.b7GgZFKG.dpbs

Thanks,

10

Hello @jerdung ,

Apologizes for my late reply, I was out and I couldn’t upgrade the firmware until today.
After upgrading REV B modem with Firmware version SWI9X30C_02.30.01.01 I can confirm the issue with the REFRESH it is not present anymore
May I ask what was the issue with firmware version SWI9X30C_02.24.05.06? I didn’t find any release notes where the issue is explained
Thank you!!!
Best Regards,
Jordi