TRM250 no USSD command possible AT+CUSD

Networking Solutions
1

Hello,

i have problems with an TRM250 modem and USSD commands.
Every time i send e.g. AT+CUSD=1,”*100#” or AT+CUSD=1,”*100#”,15
i get directly ERROR. with directy i mean directly after pressing enter. no time difference so it seams that the error comes from modem, not provider. i have only the output ERROR. not more.

i also tried AT+QCFG=“nwscanmode”,1,1 to set to gsm. no changes.
AT SMS sending works fine.

USSD commands in a cellphone or RUT241 with the same SIM-Card works as expected.
i am sitting for 2 days to solve this problem and i habe no more ideas what to do.

Can anyone please help me what i have overseen here?

Thanks and BR

Martin

3

Greetings,

We are currently working on your issue and we will get back to you as soon as possible.

Best Regards,
Justinas

4

Hello Justinas,

Thank you very much for your reply and for working on this issue.

I wanted to ask if there are any new information about this problem?

Thank you very much!

Martin

5

Greetings,

Apologies for the delayed response. I tested the USSD commands on my device and experienced the same results as you described. I’ve forwarded this issue to our Research and Development department for further investigation and will get back to you as soon as I receive an update from them.

Best Regards,
Justinas

6

Hello Justinas,
thanks for the update.
BR
Martin

7

Greetings,

You are using the correct command syntax, however USSD commands are not supported on the Quectel BG96 module
Source, Quectel’s forum: BG96 USSD error - IoT Modules / LPWA Module - Quectel Forums

Best Regards,
Justinas

8

Hello Justinas,

Thank you very much for the information and your efforts.

However, your online manual at

describes the CUSD command for the TRM250. This was a decisive factor for me when choosing the modem.

Clicking on the link at the headline also describes the AT+CUSD command for the BG96 chipset in the BG96 AT Commands Manual.

For me, there was therefore no doubt that this is supported.

This is naturally frustrating for me now, as the purchase decision was made based on an incorrect online manual.

Thanks and BR

Martin

10

Greetings,

After reviewing the matter, it appears that the modem does not support USSD, as it functions only in the PS domain, while USSD requires the 2G CS domain.

We sincerely apologize for any inconvenience or confusion this may have caused. Our documentation reflects the information we received from the modem manufacturer, and we regret if this contributed to any misunderstanding.

If you need further clarification or support, it may be helpful to contact your supplier.

Best Regards,
Justinas

11

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