Gemalto is now part of the Thales Group, find out more.

You are here

EXS82 "Unknown Internal TLS Error" | Thales IoT Developer Community

February 24, 2021 - 3:03pm, 843 views

I have an EXS82 module mounted on an LGADevKit that I’m trying to connect to the MQTT broker associated with Microsoft Azure Iot Hub. The module connects without problem with open MQTT brokers, but I get the same problem when security is involved (tried other brokers as well). This problem is that after I use the SISO command to open the connection the module tries to connect for about 10 seconds and then gives me the error: ^SIS: 1,0,62,"Unknown internal TLS error". After which I don’t get connected and I can’t use SISD to change any parameters.

I can’t find any documentation on what this error means. The module has the correct certificate in its store, the “Baltimore CyberTrust Root" (the thumbnail matches the one in Azures documentation), and I set secOpt=1. The password and username are correct, I have confirmed that by successfully connecting using the program MQTT.fx on my PC. Do I call some commands in the wrong order or is there anything I’m missing?

This is the firmware in my module:

Cinterion

EXS82-W

REVISION 01.100

A-REVISION 01.000.08

 

And this is my sequence of AT-commands:

AT+CFUN=1,1

OK

^SYSSTART

AT+CPIN=<My PIN code>

OK

AT+COPS=2

OK

AT+CGDCONT=1,"IP", "online.telia.se"

OK

AT+COPS=0

OK

AT+CREG=1

OK

AT^SISS=1,srvType,"MQTT"

OK

AT^SISS=1,conId,"1"

OK

AT^SISS=1,address,”mqtts://<My Username>:<My password>@<MY_IoT_Hub>.azure-devices.net:8883” (Other question that is far beside the point, but why doesn’t the SISS command work for setting username and password like the manual say it should?)

OK

AT^SISS=1,secOpt,1

OK

AT^SISS=1,qos,1

OK

AT^SISS=1,retain,0

OK

AT^SISS=1,clientId,"<My client ID>"

OK

AT^SISS=1,cmd,"publish"

OK

AT^SISS=1,Topic,"devices/<My client ID>/messages/events/"

OK

AT^SICA=1,1

OK

AT^SISO=1,2

OK

^SIS: 1,0,62,"Unknown internal TLS error"

AT^SISD=1,"cleanParam"

+CME ERROR: operation temporary not allowed