TRB142 serial COM with AT commands

[petbar01]

Hi,

After searching the forum I still have some questions unanswered.

My use case is to connect the TRB142 to an legacy car device, previous solution was a legacy GSM modem but this will be unsupported by the mobile network soon.
SMS should be received and transmitted transparently and immediate using PDU mode. So far this seem to be possilbe.

• Is there a list or document available for the supported AT commands of this device?
• Which AT command settings can in some way be saved in NVM so it is still active after a reboot?
• The TRB142 repeatedly transmitts some mobile network status, this may affect my serial communication with AT commands. At least it interferes with my manual AT commands. So I turn it off with AT+QCSQ=0. Can you turn this off automatically by adding this to the rc.local file by calling the command /usr/sbin/gsmctl -A ‘AT+QCSQ=0’, so it will be updated at restart?

Thank you
Regards Peter

[Martynas]

Hello,

Apologies for a delayed response.

@petbar01

Is there a list or document available for the supported AT commands of this device?

Regarding this inquiry, I assume you have Quectel’s EC21 modem on your TRB142, if so the supported AT commands manual for this module is available here: File:Quectel EC25EC21 AT Commands Manual V1.2.pdf - Teltonika Networks Wiki.

@petbar01

Which AT command settings can in some way be saved in NVM so it is still active after a reboot?

Network settings such as operator selection, PDP context, APN, and authentication parameters are usually saved after a reboot.

@petbar01

Can you turn this off automatically by adding this to the rc.local file by calling the command /usr/sbin/gsmctl -A ‘AT+QCSQ=0’, so it will be updated at restart?

Yes, you can add the following command to /etc/rc.local:

/usr/sbin/gsmctl -A 'AT+QCSQ=0'

This will disable unsolicited network status reports and ensure that the setting is applied every time the device reboots.

Best regards,

[petbar01]

Thank you Martynas!

I have read your answers and we will continue to setup the TRB unit.

During the passed time we tested and investigated the TBR unit further, and we have got one new question. Do you have any suggestions of how to achieve the task below?

We have tried to change the SMS Event Reporting Configuration with command AT+CNMI to activate immediate SMS reporting when a SMS is received. But it did not work.
We want the TRB142 modem to output this indication to our device when an SMS is received.
Short message is output directly to the TE (in PDU mode)
Syntax: +CMT:,
An example is: +CMT: ,26 "

Best regards Peter