urgent......Serial port

Linux and Unix-Like Linux
1

I think my serial port(on board) is not working ......
because when I am running same code on two machines its working good....but when my system comes into picture ....it doesnt show any output comming from serial port..........

can anybody tell me how to configure my serial port.........or to check it is installed on ot or not...........

moreover I had inserted another card having two serial ports.....
info about card:::::::::::::::::::is here
05:04.0 Serial controller: Timedia Technology Co Ltd PCI2S550 (Dual 16550 UART) (rev 01) (prog-if 02 [16550])
Subsystem: Timedia Technology Co Ltd Unknown device 4037
Flags: stepping, medium devsel, IRQ 10
I/O ports at 1100 [size=32]

but how to configure/install ....this card.
I am using fedora core 6
thanks & regards.........

2
  1. If the operating system says the device exists, eg
ls >/dev/ttyS0

if that does not return an error, the serial port is configured for the OS.

  1. The next part is RS232 debugging, here always start with a known working terminal and go through the different combinations with a null-modem and even a break-out-box.
3

but whem I am running command ::::
dmesg | grep tty
It shows:::::::
[root@arun ~]# dmesg | grep tty
Xen virtual console successfully installed as ttyS0
.....
what does it means...my onboard serial is configured or not?????
and if configured then why I am not able to send or recieve data....

4

also when I am using command::

[root@arun ~]# setserial -g /dev/ttyS0
Cannot get serial info: Invalid argument

why so??????????
i thing so that its not configured correctly............

5

Are you running as a virtual host, not a real machine?

6

Can I modift it or not??????
So how to make it real console????????
please help........

7

You don't want it as a real console, you want it connected to a serial port.

So the reasons things don't work when "when my system comes into picture" is because you don't have a real machine, everything is virtually provided by Xen. This may make writing software easier but it makes tracking comms problems down much harder because you now have to try and get the Xen environment to provide you with the real serial port.

8

I had just configured my grub .........
title Fedora Core NEW (2.6.18-1.2798.fc6xen)
root (hd0,0)
kernel /xen.gz-2.6.18-1.2798.fc6
module /vmlinuz-2.6.18-1.2798.fc6xen ro root=LABEL=/ xencons=xvcX
module /initrd-2.6.18-1.2798.fc6xen.img

and after restarting my system......when I does........

[root@arun TestReadport0]# dmesg | grep tty
serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
0000:05:04.0: ttyS1 at I/O 0x1100 (irq = 18) is a 16550A
0000:05:04.0: ttyS2 at I/O 0x1108 (irq = 18) is a 16550A
[root@arun TestReadport0]#

So here I think my device working correctly..........
1st is serial port on board....
and second & third one my new device
05:04.0 Serial controller: Timedia Technology Co Ltd PCI2S550 (Dual 16550 UART) (rev 01) (prog-if 02 [16550])
Subsystem: Timedia Technology Co Ltd Unknown device 4037
Flags: stepping, medium devsel, IRQ 18
I/O ports at 1100 [size=32]

After that I connected my cable loop backed into my ports........
my program is showing that it is opening serial port correctly but not sending any data ...
its happening why?????
any solution????????

9

Did you use a null-modem or similar to swap the TX(etc) and RX(etc) wires over?

Why do you not test

(a) by connecting to another working machine?

(b) by using a known working piece of software such as minicom at both ends?

10

yes I had used Null modem cable........

(a) by connecting to another working machine?
and I had not tested on another system...because another system is far away...and my team member is working on another module......on that system..

(b) by using a known working piece of software such as minicom at both ends?
because I dont know how to use that....I had tried earlier but not able to understand that minicom...

11

If you are writing communications software demand another machine to assist development/testing.

If you don't work with some known software/test harness you are totally in the dark until something suddenly starts working.

Please find a terminal emulator you can use, once you know the hardware/devices are configured then you can test your software.

12

this is the line that my minicom is showing me at the bottom of my terminal.....
CTRL-A Z for help | 9600 8N1 | NOR | Minicom 2.1 | VT102 | Online 00:10

but my another minicom is showing offline???
why so and no transfer of data??????whay so...........
please provide me some knowledge......how to use...I am going in dark....
why it is not receving data ???????????

13

every port is showing opening correctly..........
then also not recieving data??????
what's happening???????

14

Configure the terminal using

ctrl+A Z O Serial-Port-Setup

set the port name and baudrate,

set parity to none, handshaking to none, bits to 8bits

If you have this running on either end and you type at one end and nothing is happening then you are, what we call "not connected".

So you have to go through the process of confirming that your device name does really map to the 9 or 25 pins sticking out of the back of your machine.

And you also have to try with null-modem, or what ever combination of 9 or 25 pin dongles you have.

15

I had done what you had saig........but same problem persists............
no data transfer............

16

CTRL-A Z for help | 9600 8N1 | NOR | Minicom 2.1 | VT102 | Offline
CTRL-A Z for help | 9600 8N1 | NOR | Minicom 2.1 | VT102 | Online 00:48
these are the bottom lines in the minicom.....
why one is online and another is offline??????????

17

Ignore the issue about the online/offline status, sort out the connectivity.

Find *anything* that has RS232 connectivity that you can trust, a windows box with HyperTerminal, a MacPlus running VersaTermPro, an old daisywheel printer, anything that you can use to prove you know you can talk out and/or in.