Can TRB256/RUT955 transmit a start command via RS232 in 'Serial over IP' mode

Networking Solutions
1

Dear Teltonika Community,

I am very new here.
ChatGPT - Gemini and Grok could not help me anymore so trying my luck here.

I am trying to connect a Scarlet WindPro sensor to my Teltonika gateway (TRB256/RUT955). The goal is to send a start command to the sensor and then read the continuous data stream over the network.

The connection works perfectly when using a computer with terminal software (like CoolTerm). The key to success is sending the command in “Line Mode,” which ensures the correct CR+LF termination.

The problem arises on the Teltonika gateway. When I configure ‘Serial over IP’ (in TCP Server mode), I am unable to send the start command. It appears this mode can only receive data from the RS232 port, but cannot transmit data to it.

Important test: If I first start the sensor with my computer and then connect it to the Teltonika gateway (while it is already sending data), the data is correctly received through the ‘Serial over IP’ connection. This proves that receiving data works, but transmitting the initial command does not.

My question is: How can I configure the gateway to transmit an initial ASCII string (like QINFO-START with a CR+LF) to the RS232 port, in order to then receive the data stream? Is there a script (Lua, shell) or another mode that supports this initial two-way communication?

Thank you for your help.

3

Good afternoon,

You can connect our router/gateway to your Scarlet sensor to support bidirectional communication over TCP/IP using their RS232 serial ports.

One device is set as a TCP Server, the other as a TCP Client connecting to the server’s IP and port. Both devices then can send and receive serial data through their respective TCP connections.

I would advise to follow this guide, and let us know if you encounter any issues : Bidirectional communication between two serial devices over TCP/IP - Teltonika Networks Wiki

Regards,

Arturas

4

HI Arturas,

Thank you for reply-ing. But this is not the answer i was looking for.
Before the Sensor starts sending data i have to give an commando.

For example:

  • Sensor is online.
  • 955 / 256 is online.
  • 955 / 256 → Send commando to sensor: QINFO-START.
  • Sensors starts sending data.
  • 955 / 256 recieves data and starts sending to IOT platform.

Thanks again!

5

Hi there,

This is the method advised to be used in your use case. You may be able to achieve this by using a custom script, however that would be above the scope of our assistance. In regards to Teltonika advice, as above mentioned:

I would advise to follow this guide, and let us know if you encounter any issues : Bidirectional communication between two serial devices over TCP/IP - Teltonika Networks Wiki

Regards,

Arturas

6

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