sim hot swap problem with Telit GE910-QUAD

[Tim Small]

On 20/07/17 09:09, Carlo Lobrano wrote:
> 
>> I think that the commands which mm issue causes it to close and reopen
>> the SIM and this takes longer than mm is giving it.  How should I work
>> around this?
> 
> This modem has an unsolicited signal (QSS) that shows the presence and
> status of the SIM.

I think the problem may be connected to the issuing of the AT+CSIM=1
command to directly interact with the SIM card after "AT#QSS=1" mode is
enabled? - from the AT Commands Reference Guide for Telit modems, "Rev.
24 - 2016-09-07", page 176:

"After the locking of the SIM-ME interface (AT+CSIM=1) the SIM will be
accessible only by AT+CSIM commands (#QSS: 0)."

http://www.telit.com/fileadmin/user_upload/products/Downloads/2G/Telit_AT_Commands_Reference_Guide_r24.pdf

This is consistent with this behaviour I see on the terminal:

--> AT+CSIM=1
<-- OK
<--
<-- #QSS: 0
--> AT+CSIM=10,0020000100
<-- +CSIM: 4,"63C3"
<--
<-- OK
<--
--> AT+CSIM=0
<-- OK
<--
<--#QSS: 1


... if you issue a +CSIM=1 command and then don't do anything, the lock
command (+CSIM=1) command eventually times out, and at that point you
get an unsolicited '#QSS: 1'.

This is unconnected to any physical movement of the SIM card (I've
verified that seems to do the right thing too - after issuing
"AT#QSS=1", you get appropriate unsolicited messages when you do really
remove/replace the SIM card).

Here's a more relevant extract from the debug log:

https://gist.github.com/tim-seoss/acd3624cfbe46a28faebb29a66045432

in particular around line 82, 83 it looks like there's some sort of race
going on with the pin lock checking and init command streams getting
issued at the same time and eating each other's responses?

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