Question

I want to connect a datalogger to the RS232 port of a RUT955. The datalogger has a DCE port so I have used a DCE to DCE crossed cable to make the connection between both devices. The datalogger outputs data at 57600, 8 bits, no parity, 1 stop. It does this every 10 seconds. I can see the data from the datalogger on my laptop when I use a RS232 to USB converter and a straight through cable.

But I cannot see the data coming through on the RUT955. I am using PuTTY and the command cat /dev/ttyS0

Is there some setup necessary that I am missing to get the ports communicating?

Answer 1

Hello.

You have multiple protocols available to get data from a serial device and send it over internet.

The easiest one is to setup a TCP listener in one PC that have public IP and Port available.

In that PC you can run a very simple TCP server (Like Hercules Software) and receive simple ascii data strings from the device.

You will have to point the RUT955 to send TCP strings to that simple server.

In the link below is more reference to that.

https://wiki.teltonika.lt/view/RS232/RS485

Comments

Thank you for replying but I am still having a problem.

I have a RUT955 with a SIM card inserted. I want to connect the DB9 (RS232) port on the front of the RUT955 to the DB15 (RS232) port on the datalogger. I have made the crossover connections between each port using the following, the cable is 1m long:

Pin 2 (RXD) RUT955 (DB9) connected to Pin 3 (TXD) Datalogger (DB15)

Pin 3 (TXD) RUT955 (DB9) connected to Pin 2 (RXD) Datalogger (DB15)

Pin 5 (GND) RUT955 (DB9) connected to Pin 10 (GND) Datalogger (DB15)

I do not want to use any PC, only the RUT955 and the Datalogger. I can already send data to a server using the SIM card. The issue I have is the communication between the RUT955 and the Datalogger. I have enabled RS232 on the RUT955 and set the correct baud rate. The only way I know to see if the RUT955 is receiving the data from the datalogger is by using PuTTy and the command cat /dev/ttyS0. I though that this command would show me any data received on the RS232 DB9 port?

I know that the datalogger is sending data because I can receive it when I connect the datalogger to the serial port on my PC. The datalogger sends data every 10 seconds, it does not wait for any ready signal from the receiver.

So, how can I view the RS232 port on the RUT955 to see what data it is receiving?

Thanks for any assistance

Answer 2

I am trying the same. I can at least send data from RUT955 to my Computer using:

echo -ne 'Hello ' > /dev/ttyACM0
and HTerm at the other side.

So you could try cat /dev/ttyACM  intead of  cat /dev/ttyS0  to look for received data.

For me it does not work. I guess its beacuse RS232 is configued to be used as login console? But i am not sure.

UPDATE: When I use:

microcom -t 99000 -X /dev/ttyACM0

I am able to get data as well.

Comments

Thank you for your help. This has solved the issue that I was having and I am now able to receive data using the command cat /dev/ttyACM0.