Question

I've got a TRB145 on my desk as Modbus master and intendet to use SMS to trigger Modbus commands to finally steer outputs.

Everything seems clear except that I don't see a way to use SMS to send preconfigured data to a Modbus slave.

Is this possible at all?

Meanwhile, I've read other tickets surrounding the same theme. The anwer was always 'not possible'.

I'm asking myself what the serial Modbus master and its ability to set coils shall be used for. It only makes sense to me when it's possible to issue the conditionally.

I could imagine 'virtual I/O' that could be set and read using the current SMS tool. And the use this virtual I/O to be sent out to the Modbus slave either by using a mapping mechanism (virtual I/O <-> Modbus address) or to trigger Modbus rules.

Thanks in advance

Comments

I've seen that in the latest firmware there are are no improvements for this and I'm sure that it would greatly improve the product if a developer could add this.

Feature Request:

Trigger an arbitrary shell script upon SMS/call/mail/http/...

Would that be a huge work to be done?

Answer 1

Hello,

Do I understand correctly, that you want to send SMS message to gateway and control connected slave devices? If this is so, then router does not have this functionality out of the box.

Best regards

Tomas

Comments

Hi Thomas

That is what I've learned already and I understand it halfways.

What I do not really understand is: why is there no option to trigger a script by SMS as least? It is true that I could implement a timed polling mechanism via cron and gsmctl and then send commands directly to /dev/rs485. But I do not like the long minimum polling interval caused by the use of cron and needing to reinvent the wheel by creating my own Modbus master. But anyway, there is a first possible solution.

If there was a possibility to trigger scripts by SMS, one could modify the serial Modbus master configuration in order to send out different commands to the Modbus slaves. It could be accomplished by UCI over SMS already but this is not to be used by the end user.

The reason why I was mentioning virtual I/O: every existing tool inside the TRB can handle I/O. If it was possible to create such virtual I/O and use it as a variable source inside the modbus data, then that would be a most versatile solution without focussing too much on SMS.

I haven't had a look at the SDK but I imagine that I could not extend the existing webui with it. I mean, I could not extend the existing V2.04 with custom dialogues. Or if yes, would there be a chance to get such modifications into the standard product? It would be bad if a customer wiped out all by updating the firmware.

Regards,

Martin