TRB - 140 Not possible to Send SMS via Modbus TCP

Dear Ladies and Gentlemen,

i tried to send SMS usiing the corresponding Modbus Registers to send a specific SMS using Modbus TCP on the TRB 140.
I already did this with a TRB142 abd Modbus RTU and it works very fine.
I have no issues sending the information for the SMS to the registers 397 - 487 (including the telephone number with leading 00 and the SMS text) but as soon as I send the 1 to the 396 register, sometimes a SMS is sent (with a timeout message) sometimes just a timeout message occurs and sometimes the complete modbus communication crashes.

Edit: After some more tests: SMS is always sent but it takes about 3 Minutes. First the modbus communication crashes and after the communication is stable again (~ 3 Minutes) the SMS is sent.

Can you plese support me with my problem?

Thank you

Hi,

It seems like the problem you’re facing is because you’re attempting to send a large number of registers in a single request. Specifically, you’re trying to send registers from 1 to 396, which is almost 400 registers. In Modbus RTU and Modbus ASCII, there’s usually a limit of 125 registers per function code in a single request due to the constraints imposed by the Modbus frame size.

To resolve this issue, try reducing the number of registers you’re attempting to send in a single request and check if it resolves the problem.

Best regards,

Marijus

Dear Marijus,

thank you so much for your reply.
Actually I am just sending the needed amount of registers (depending on the length of the message) which is about 10.

Anyway it is working right now also by using the POST/GET command.
The only difference now is that the TRB140 has now an active data connection (either to the Mobile internet or to the wired internet). As soon as I disconnect the data connection and use the TRB140 only for sending SMS the mentioned issue pops up. Any advice on this because I want to use the TRB140 only with a sim card which can be used to send sms and without data.

Thank you!

Hi,

It’s a bit challenging to pinpoint the issue. Could you please share screenshots of the Modbus TCP and SMS sending settings? Additionally, obtaining logread information would be helpful in understanding what’s happening during the issue.

To get logread information, connect to the device via SSH and execute the command “logread -f”. Then, attempt to send an SMS and wait for the error message to appear. Copy the logread output for a more accurate identification of the problem.

Best regards,

Marijus

Dear Marijus,

now also after deactivating any connection to the Internet it is working perfectly.
So I cannot send you any log because I can’t reproduce the error.
Is there anything known that I have to connect the TRB to the internet just for one time to update the Date/Time…or whatever?

Thank you and best regards

Hi,

If you come across a similar issue in the future, please obtain a troubleshoot file before resetting the device. Create a new post on this forum, and we’ll make an effort to provide better assistance.

Regarding connecting the device to the internet during setup, it’s not necessary.

Best regards,

Marijus

This topic was automatically closed after 15 days. New replies are no longer allowed.