Send SMS - TRB140

Hi all members. I’m a new user of Teltonika’s device. I use TRB140 to send SMS Alarms from PLC. I have 2 issues that need your help.

Issue 1:

My device is running with firmware TRB1_R_00.07.04.5 but it’s difficult to read and write some registers as below:

(Follow the document on your website TRB140 Modbus - Teltonika Networks Wiki ( )

  • “Send SMS” - Register Address is 396. I use “Modbus Poll” to scan addresses and it says " 02 Illegal Data Address". I also tried with the PLC address but it still does not work so I can not trigger the Alarm.

  • “Add SMS” - the register starts from 397 and its array is 90 registers. I scanned and got these but I can adjust only the first register but can not with the others containing phone and contents and it also says " 02 Illegal Data Address".

→ So is it related to firmware or the compatible software?

Issue 2:

I am building a small demo project with PLC using TRB140 to send SMS alarms triggered by a signal from PLC. So can I create registers that have individual content and are sent to group phone numbers? Could you please share with me how to do that or some related documents? I have found documents on your website and social media but I can not do that. I appreciate your help.

Thank you so much.


For information on how to send SMS messages via Modbus Registers on TRB140, you can refer to our wiki page here. It shows the steps, and overall structure and format for the configurations.

Regarding SMS triggering from a PLC, I recommend exploring the concept of Modbus Alarms. These alarms enable you to monitor Modbus registers on the PLC, and in the event that the register value changes, the TRB140 will send an SMS message. It’s important to note that the SMS message remains constant. Thus, if you require different messages, you’ll need to set up multiple alarms and monitor distinct registers accordingly. Moreover, the configuration permits you to specify multiple recipients for these SMS notifications. If you are using MQTT, you can also send MQTT messages instead of (or in addition to) SMS. For more information, please, take a look at our wiki page here.

Kind Regards,

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Thanks for the answer, Now I can write content to register 398, but I can not write the “send command” by setting value 1 to register 396 (also 397). It says: Failed to get response: salve device or server failure. Is it caused by the newest firmware 07.04.5?
Could you please help me with what wrong is?
I would like to ask 1 more question: Does the TRB140 has each register for each alarm (likely a channel for the alarm then using Modbus point from plc to trigger this channel)?
Thank you.

here some picture that I tested


The error can be a result of invalid information in the SMS registers. Maybe the phone number is incorrect or the format is wrong? For example, if you are writing with HEX, the values should start with ‘30 30’ which is basically ‘00’ or ‘+’ that you need to specify before entering the country code and the phone number.

I am not sure if I understand the second question fully. The Modbus alarms are monitoring the specified Modbus registers. Basically, this can be your TRB (as a modbus slave) or your PLC. So, for example, you have 2 alarms - one monitors register A on PLC, and another alarm monitors register B. If value A changes, the first alarm is triggered and SMS messaged configured within that first Modbus alarm is sent.

Kind Regards,

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