# [solved] Serial console connection problems

## fangorn

Hi, 

I am trying to connect to the serial console of a WRAP board. 

None of my computers has a serial port any more  :Rolling Eyes:  so I use a USB to serial converter in a USB docking station. Or at least I try to. 

```
 -> dmesg

...

pl2303 1-6.3.4:1.0: pl2303 converter detected

usb 1-6.3.4: pl2303 converter now attached to ttyUSB0
```

According to some sources I setup minicom like this

```
# Machine-generated file - use "minicom -s" to change parameters.

pu port             /dev/ttyUSB0

pu baudrate         19200

pu bits             8

pu parity           N

pu stopbits         1

pu minit            ~^M~

pu rtscts           No

```

But as soon as I start minicom and try to connect to the serial port I get 

```
pl2303 ttyUSB0: pl2303_open - failed submitting interrupt urb, error -28
```

The only reference I found to this are for a problem  with the 2.4.34 kernel driver. 

```
-> uname -a 

Linux frodo 2.6.26-gentoo-r1 #7 SMP PREEMPT Wed Jan 28 20:39:04 CET 2009 x86_64 AMD Turion(tm) 64 X2 Mobile Technology TL-60 AuthenticAMD GNU/Linux

```

I know this is more of a hardware problem, but I thought in the networking sector I got better chances an experienced admin sees this. As you may have guessed, this is the first time I need a serial console. I need to see why it does not start up to network connectivity.

I hope someone can help me. 

fangorn

Edit: on the machine is a specialized linux distribution (voyage linux) so I think lilo is configured correct to access the console. I got the baud rate from it's lilo.conf.

Edit 2: 

Hardware now seems to be ok. Now I have a config problem with minicom.

----------

## Janne Pikkarainen

Maybe you have an USB 2.0 port and that's too fast for that kind of hardware? At least a little bit of googling hints to that.

See here for some sysctl tunables.

----------

## fangorn

Thanks, I did miss that one.   :Embarassed: 

Will try this evening.

----------

## fangorn

Strange.

If I issue

```
echo -n 11 >/sys/class/usb_host/usb_host1/companion
```

I get 

```
echo: write error: No such file or directory
```

If the Docking station is not plugged in nothing else happens. 

If the Docking station was plugged in and I unplug it, the monitor goes blank and the machine does not react any more.

----------

## fangorn

OK, I got myself a USB 1.1 serial converter.

Now I can connect minicom to the WRAP. But I get 

```
rUE��UEו��2Q��E�4ۇE�4ۇE�4ۇE��4Q����tۇE�4ۇE��4Q��E��4Q��E��4Q��E�tۇE��4ۇE�4ۇE��4Q��E�EC�GTQ     �

```

I am not an expert in communication over serial, but I think something is going wrong here.   :Twisted Evil: 

On the homepage of the Hardware I found the tip:

 *Quote:*   

> If you can't get into setup, please disable serial port hardware handshake in your terminal emulator.

 

But how do I do that in minicom?

Thanks for any tips. I am really stuck here. 

fangorn

----------

## billium

I use serial quite often, and use the Prolific adapters you talk of in your first post without any problem.  This is what I get from dmesg when plugging in the device:

 *Quote:*   

> usbserial: USB Serial support registered for pl2303
> 
> pl2303 2-6:1.0: pl2303 converter detected
> 
> usb 2-6: pl2303 converter now attached to ttyUSB0
> ...

 

I use these both on usb 1.1 & usb 2 computers.  Setserial does not work with these though.

minicom -s will give you the setup dialogue, select serial port setup, select  F to toggle hardware flow control.

Your o/p looks more like wrong baud rate though.

cutecom is also worth a try if you are using X. 

Billy

----------

## fangorn

Good tip with Cutecom.

Got me testing my settings. Connection speed was too low. 

Thanks again for all your efforts. 

fangorn

----------

