[SOLVED] GTKTERM on debian 12 does not display data

[amorales]

I am using gtkterm 1.2.1 on Debian 12 to monitor serial data sent to another machine via serial port RS232. At first I was successful in transferring data from machine to machine, but after months of not using it I have not been able to do the transfer. Looking for what could be the problem I did the following simple test: transferring a file between the tty port and the ttyS0 port of the same machine, using gtkterm internally connected to the serial port ttyS0.The command was: cp asciifile /dev/ttyS0, where asciifile is an ascii file. Nothing is transmitted to the gtkterm display.The command to associate gtkterm with /dev/ttyS0 was gtkterm -p /dev /ttyS0. I assume that all the settings are automatically set with that command. The permissions for /dev/ttyS0 are correctly given.I believe this simple test shows that something essential is wrong and I would appreciate any suggestions that would allow me to find a solution to the problem.
A similar problem is reported in this forum:
gtkterm does not respond for serial connection
BrownBear1968Jan 13, 2020Jan 13, 2020Linux Software

 

[KlausST]

Hi,

You only talk about ttyS0 (as far as I understand). So you either need an external feedback (Tx--> Rx) or you need two ports.
(I don´t understand what you mean with "connected internally")

The basic question is:
* is the file not SENT correctly
* or is it not RECEIVED correctly

On a real port you may use a scope to find out.
You also may use a second computer to find out.

Correct port setup is essential. Also the wiring (according the setup, like handshake signals).

Klaus

 

[amorales]

Hi,

You only talk about ttyS0 (as far as I understand). So you either need an external feedback (Tx--> Rx) or you need two ports.
(I don´t understand what you mean with "connected internally")

The basic question is:
* is the file not SENT correctly
* or is it not RECEIVED correctly

On a real port you may use a scope to find out.
You also may use a second computer to find out.

Correct port setup is essential. Also the wiring (according the setup, like handshake signals).

Klaus

 

[amorales]

Hi KlausST:

Hi,

You only talk about ttyS0 (as far as I understand). So you either need an external feedback (Tx--> Rx) or you need two ports.
(I don´t understand what you mean with "connected internally")

The basic question is:
* is the file not SENT correctly
* or is it not RECEIVED correctly

On a real port you may use a scope to find out.
You also may use a second computer to find out.

Correct port setup is essential. Also the wiring (according the setup, like handshake signals).

Klaus

You are correct in saying that I need two machines to pass digital information through the serial ports. That is exactly what I was doing successfully a few months ago.But now, with the same two machines I can no longer do it and I am looking for where the problem is.I made some progress since yesterday but I still have some problems.I will answer your first observation: (I don´t understand what you mean with "connected internally"). If on a single machine I give the command "gtkterm -p /dev/ttyS0", then I have the machine internally connected with gtkterm. For this reason if I give in the shell the command "cp asciifile /dev/ttyS0", I would expect the asciifile to appear in the gtkterm window. But this does not always happen. Incidentally, if I give the command "cp asciifile /dev/tty", the asciifile appears in the shell, but not always. This explains the expression "connected internally" since there are no external cables. My machine only has one RS232 port so I can't use a null cable.Now I'll explain the current situation with two machines. On machine 1 I give the command gtkterm -p "/dev/ttyS0" with the corresponding permissions. On machine 2 I give the command gtkterm -p "/dev/ttyUSB0" with the corresponding permissions. To connect machine 1 with machine 2, I used an RS232 to USB converter cable. Now the command "cp asciifile /dev/ttyS0" is executed correctly displaying "asciifile" in the gtkterm window of machine 2. Also, every character typed in one gtkterm window appears in the other. That is: everything is working correctly and I thank you for your answer that motivated me to find the solution.