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+1 vote
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Hello there.

Is there is a possibility to forward serial data(RS232) over a Mobile Network converted into TCP/IP? I tried configuring the Serial Port (Over IP) and set the mobile network parameters according to my SIM Card installed(Mobile Network is connected successfully) but can't seem to find any possibility to successfully send data.

Kind Regards

3 Answers

0 votes
by anonymous

Can you send a screenshot of your RS232 configuration and add device datasheet?

Also, have configured allowed to connect IP address? For testing purposes I suggest to use

Thank you for the quick reply.

This is how the RS232 configuration is made. I've set to allow all IP Adresses via WAN Interface. Is this configuration right? 

This is the device I used:
The serial device used has a simple RS232 interface with only RXD,TXD and Common Pins connected.

by anonymous
Have you tried to test this setup in local network, i.e using some serial monitor (Hercules for Windows) on computer which is connected to router via LAN?

Also, why you are using port 80?

We could figure out the issue. The problem was that we used a straight-through Male/Male cable instead of a crossed Null Modem cable. The configuration was set up just as shown above and it worked well. 

To answer your question: We set up all communications with our server through TCP Port 80

Thank you again

Hello, i have a question. We are trying to get some data from RS232 to TCPIP to send it on our webservice which is on windows IIS. We setup a connection like you did. But we dont know how to call this. We know we must open a bridge connection from our server to TELTONIKA. Do you know something about that? Thanks.
by anonymous
Hello, MIHA91,

Can add your RS232 configuration printscreen?

Hello thanks for the quick response, here are the RS232 settings:

How do we open a connection from our webserver IIS to teltonika to listen the RS232 port. Is there a program to test or what?

by anonymous


It looks that your server IP address is private and you cannot reach it via internet, if your router and server are not in the same LAN or APN network.

For testing on windows I suggest to use Hercules SETUP utility ( with linux use netcat and echo commands.

Also, what is your network topology, since without it's hard to understand your configuration.

Hello. Thanks for the response. No the ip is correct, because we have private VPN connection with IPSEC with the provider, so the SIM CARDs, can reach us over the private network. This works 100% because we are using this for other FTP services and some other devices that can reach us with that IP.


WS 2019 - IIS - IP for testing purposes without any FW on the windows.

Then the router with IPSEC over APN with the provider, every port is allowed to our VLAN through router FW, again for the testing purposes...

Then the providers side, with RADIUS and everything

Then the teltonika modem.

Do you know if anything is comming to RS232 and you have this setup, does this mean that the teltoinka is forwarding to that address and port? because in the wireshark on the server, there is nothing coming on this ip or port,... Thanks.
by anonymous

To check if anything is coming to RS232 port, connect to router terminal via CLI or SSH ( and with command cat /dev/RS232 collect data from it. If information from RS232 device was sent to router, you will be able to see it.

For testing setup, I suggest to try it locally. Connect router to computer, on which you are running Hercules server to see if basic communication between Server <-> Router <-> RS232 device is working.

Talking a about port opening. For OverIP communication, port is opened automatically when you enable RS232 service.

Hello Tomas, thanks for your help, we tried the settings and the program herkules and now it works, i dont really know what was wrong, but we change the teltonika, and try your seetings and recomendations, and then it started working, now we must to format the web service on iis to listen to those ports and then we are done,... THANKS...
0 votes
by anonymous

I was also interested in this issue. program was enough for me to solve to forward serial data over the network.

Thanks for the advice, though

0 votes
I got a new question on the same serial-over-ip issue. If I use rut955 to collect serial data from a legacy device, is this data buffered before it is send to the configured IP-server ? If not, when is it sent ?
by anonymous
It collects data when it is requested. If there's no way to generate the constant data flow it will generate new data at the point it is requested.

I'm affraid I don't understand what you mean and this feature is absolutely vital for us. "when it is requested..." but how and where ? We will use this feature in a request-reply communication where the request is send by the server and the replay is generated by legacy equipment on the rs232-connection.