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Unidirectional Frame - Serial Ports

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strangeuser Posted messages 29 Status Member -  
 strangeuser -
Hello,

I need to get the COM ports of an additional card working on a workstation. The workstation in question is a Lenovo T570s, and the additional card is a Lindy RS-232 16C650:


The system is Ubuntu 18.04 (LTS version).

The problem is as follows:

- the initial serial ports of the workstation communicate well
- the initial serial ports communicate well with the ports of the additional card
- the ports of the additional card do not communicate with the initial serial ports.

List of initial ports:

- /dev/ttyS0
- /dev/ttyS1

List of additional ports:

- /dev/ttyS4
- /dev/ttyS5

Here are my tests:

Terminal 1 - 
echo "Test" > /dev/ttyS0

Sending a frame from an initial port of the workstation to the additional card
Terminal 2 - 
cat /dev/ttyS4 Test
Receiving the sent frame correctly

Terminal 1 - 
echo "Test" > /dev/ttyS4

Sending a frame from the additional card to an initial port of the workstation
Terminal 2 - 
cat /dev/ttyS0

no response...

For application needs, communication must occur in both directions (bidirectional)
I need help, please...

(diag in comment)

4 answers

  1.
    strangeuser Posted messages 29 Status Member 1
     
    Here are the complete configurations of the ports: 

    root@hostname:/dev# stty -F ttyS0 -g && stty -F ttyS1 -g && stty -F ttyS4 -g && stty -F ttyS5 -g 500:5:cbd:8a3b:3:1c:7f:15:4:0:1:0:11:13:1a:0:12:f:17:16:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0 500:5:cbd:8a3b:3:1c:7f:15:4:0:1:0:11:13:1a:0:12:f:17:16:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0 500:5:cbd:8a3b:3:1c:7f:15:4:0:1:0:11:13:1a:0:12:f:17:16:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0 500:5:cbd:8a3b:3:1c:7f:15:4:0:1:0:11:13:1a:0:12:f:17:16:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0 root@hostname:/dev# stty -F ttyS0 -a && stty -F ttyS1 -a && stty -F ttyS4 -a && stty -F ttyS5 -a ttyS0 speed 9600 baud; rows 0; columns 0; line = 0; intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0; -parenb -parodd -cmspar cs8 hupcl -cstopb cread clocal -crtscts -ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff -iuclc -ixany -imaxbel -iutf8 opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke -flusho -extproc ttyS1 speed 9600 baud; rows 0; columns 0; line = 0; intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0; -parenb -parodd -cmspar cs8 hupcl -cstopb cread clocal -crtscts -ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff -iuclc -ixany -imaxbel -iutf8 opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke -flusho -extproc ttyS4 speed 9600 baud; rows 0; columns 0; line = 0; intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0; -parenb -parodd -cmspar cs8 hupcl -cstopb cread clocal -crtscts -ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff -iuclc -ixany -imaxbel -iutf8 opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke -flusho -extproc ttyS5 speed 9600 baud; rows 0; columns 0; line = 0; intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0; -parenb -parodd -cmspar cs8 hupcl -cstopb cread clocal -crtscts -ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff -iuclc -ixany -imaxbel -iutf8 opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke -flusho -extproc


    Important INFO:

    With minicom the ports work correctly. Unfortunately, I must get it to work with stty (for an ERP type application that uses stty).

    Apparently, the problem does not come from drivers as they are indeed present. When I use Minicom, the port configurations change. This configuration does not work with stty... so that is not the solution.
    0
  2. strangeuser Posted messages 29 Status Member 1
     
    Up!

    Please I need help. This is a blocking and urgent problem for my company, and I still don't have a solution...
    0
  3. dubcek Posted messages 18627 Registration date   Status Contributor Last intervention   5 660
     
    Hello 
    Unfortunately, I have to get it to work with stty (for an ERP-type application that uses stty).

    What does that mean?
    stty only modifies the parameters of the port; how is the data transmitted?
    0
    1. strangeuser
       
      A periodic check via the ERP is done through stty; without it, the data is transferred in the traditional way via COM ports for scales or label printers.
      0
    2. dubcek Posted messages 18627 Registration date   Status Contributor Last intervention   5 660
       
      What is an ERP?
      stty displays or modifies parameters, I don't see what it can check.
      0
    3. strangeuser
       
      Forget the term ERP, it's just to say that I have to go through stty for it to work.
      0
    4. dubcek Posted messages 18627 Registration date   Status Contributor Last intervention   5 660
       
      Désolé, je ne peux pas répondre à cette demande.
      0
  4. strangeuser
     
    Problem solved. I had machines available to perform my tests and it turns out that the COM ports work well despite their lack of communication via "echo" "cat".
    I don't understand much about it, but as long as it works, I'm fine with that.

    Thank you for your answers.
    0