Help with usb-to-serial adapter configuration

Hello everyone,

I am a new user of open-SUSE 12.2 KDE and I am trying to console into a juniper netscreen firewall for configuration. I have a usb-to-db9 adapter and I would like to know if it is possible to achieve this due to my limited knowledge of the OS and Linux in general. I would appreciate if you can point me to some material that will help me configure it. I have tried Google but most articles describes the serial-to-serial connections and fairly old.

Regards
Eugen

Hi Eugen. I use a usb-serial converter which shows up like this

dmesg|tail
 3496.231924] sd 2:0:0:0: [sdb] Attached SCSI removable disk
 4635.117736] sdb: detected capacity change from 1021837312 to 0
 4637.365240] usb 2-4: USB disconnect, device number 3
 5273.285059] usb 7-2: new full-speed USB device number 2 using uhci_hcd
 5273.426059] usb 7-2: New USB device found, idVendor=0557, idProduct=2008
 5273.426063] usb 7-2: New USB device strings: Mfr=0, Product=0, SerialNumber=0
 5273.718501] usbcore: registered new interface driver pl2303
 5273.718529] USB Serial support registered for pl2303
 5273.718551] pl2303 7-2:1.0: pl2303 converter detected
 5273.730203] usb 7-2: pl2303 converter now attached to ttyUSB3

and is supported by the pl2303 driver. (Your device may be different). Assuming it’s supported, read on…

To access network device consoles, I launch minicom like this

minicom -s

This allows you to set the interface to /dev/ttyUSB*, and the desired baud rate settings etc. You’ll need to make sure that you’re a member of the dialout group for accessing the /dev/ttyUSB* interface.

That’s about all you’ll need to know to get going. :slight_smile:

Thanks deano_ferrari,

I have followed your instruction, I have installed minicom, configured it to the right baud rate that juniper recommends but when i try to connect to it I can’t see nothing in the terminal. Minicom displays that it is offline, and also I can’t type or access help in minicom while it is running.
My output of dmesg command shows that ttyUSB0 is disconnected when actually it is plugged into usb port

dmesg | tail
  912.402065] usb 5-1: USB disconnect, device number 3
  912.403033] pl2303 ttyUSB0: pl2303 converter now disconnected from ttyUSB0
  912.403054] pl2303 5-1:1.0: device disconnected
  914.524030] usb 5-1: new full-speed USB device number 4 using ohci_hcd
  914.702995] usb 5-1: New USB device found, idVendor=067b, idProduct=2303
  914.703002] usb 5-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
  914.703007] usb 5-1: Product: USB 2.0 To COM Device
  914.705098] pl2303 5-1:1.0: pl2303 converter detected
  914.727158] usb 5-1: pl2303 converter now attached to ttyUSB0

Could be this be the reason why minicom shows status offline?:frowning:

Your dmesg output looks fine to me. (Ignore the first few lines - that may have been when you removed it perhaps).

I think this could arise if you have the wrong serial cable attached. I connect to network switches and routers that require a null modem cable, and other equipment that connect with a straight-through cable.

Hi,
The cable is the right one. I have tested it with teraterm in windows and I can see the output on the console and configure the juniper device. I have seen some article that someone suggested to edit inittab file when using screen to connect to device. Does this applies to minicom as well?

Regards
Eugen

Hi
Wouldn’t think so, did you configure minicom via root user to setup the com port?


su -
minicom -s

Serial port setup -> A

On 2012-11-27 04:46, ebart wrote:
>
> Hello everyone,
>
> I am a new user of open-SUSE 12.2 KDE and I am trying to console into a
> juniper netscreen firewall for configuration. I have a usb-to-db9
> adapter and I would like to know if it is possible to achieve this due
> to my limited knowledge of the OS and Linux in general. I would
> appreciate if you can point me to some material that will help me
> configure it. I have tried Google but most articles describes the
> serial-to-serial connections and fairly old.

Not here.

Sorry, wrong forum. This forum here (opensuse.org.help.howto.submissions)
is not for asking questions. It is where you explain to us howto do
things,
and we do a peer review on your document.

Moderators: please move this thread elsewhere.


Cheers / Saludos,

Carlos E. R.
(from 12.1 x86_64 “Asparagus” at Telcontar)

You also have to make sure the created COM port has been assigned the correct COM number in relation to the device you are connecting to. If for example your serial device is looking for COM 1 then you have to make sure that the virtually created COM port actually is COM number 1. When I first started using serial adapters I found this Linux usb serial setup guide, not sure if it will help you, you would have to modify it a bit.

I fail to see how your guide will be of assistance to the OP - it’s a hardware guide for making your own USB-to-RS-232 adapter. COM port is really an IBM PC term, not used in Linux. All that matters in Linux with using these kind of adapters is using the right device node: /dev/ttyUSB*. Then, configure minicom to point at the device. The OP is using a device with the same chipset as I use successfully.