Can't access remote console

cdsJerry

@stephenw10 I built a Debian Linux machine but I'm having trouble installing the driver due to my lack of Linux experience. I have Putty installed but not the driver so it's not able to connect yet. I don't have a tty/USB0 connection showing. Instead it says /dev/ttyS0 I'm assuming this is because there's no driver.

I have several very busy days ahead of me on other projects so it may be a bit before I can get back to this. I hadn't expected it to take this much effort just to access the console.

cdsJerry

@stephenw10 My Linux skills (or rather the lack of them) are limiting me. I got a Debian machine built but I can't figure out how to create a com port nor how to install the drivers. When I try to enter the commands I find on the help pages it usually comes back as an unknown command. I'm just lost at this point.

The console is dead to Windows and my Lixux sucks.

stephenw10

You should just be able to run something Live from CD or memstick. No need to install.

What version of Debian are you using? Anything recent will have the driver in kernel already.
Try running dmesg at the command line, then connecting the console and running it again. You should see some new messages from the USB connection.
For example on mt Linux Mint box here I see:

[16678.494072] usb 2-2: New USB device found, idVendor=10c4, idProduct=ea60, bcdDevice= 1.00
[16678.494078] usb 2-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[16678.494082] usb 2-2: Product: CP2104 USB to UART Bridge Controller
[16678.494085] usb 2-2: Manufacturer: Silicon Labs
[16678.494088] usb 2-2: SerialNumber: 01327307
[16678.495946] cp210x 2-2:1.0: cp210x converter detected
[16678.498315] usb 2-2: cp210x converter now attached to ttyUSB0

I can then open ttyUSB0 with screen /dev/ttyUSB0 115200.
You may need to use sudo with that depending on your user.
To escape screen press ctl+a then k then answer y.

Steve

cdsJerry

@stephenw10 I already wiped out a Windows machine so I could do this. I installed Debian 4.19.194-2. When I run the dmesg the second time I do get a line just like your last line. I then open Putty and set the port to /dev/ttyUSB0, speed 15200, 8, 1, none, xon/xoff and click open.... and nothing happens. It's exactly the same as what's happened on all the other computers.

stephenw10

So it refuses to open (like in Windows) or it opens and shows no output?

No errors shown?

The current version of Debian is 10.10. That looks more like a kernel version but it's still quite old.
The driver has been in there for a long time though so it should still work.

cdsJerry

@stephenw10 It doesn't open at all. Exact same result as when I tried it with Windows. I click the Open button and literally nothing happens. No errors, no window, no blank window... absolutely nothing.

I wonder why my version is so old. I just downloaded the ISO from debian.org yesterday. I don't know how to make up update. I've found that yum doesn't work at all. I've done apt-get update and it insists that I put my DVD back in the drive. It doesn't seem to be getting online updates? Probably a repository error from the install but again... I don't know how to change it. This is my problem, I just don't use Linux enough to know what I'm doing.

stephenw10

If you try using screen instead of putty? Any error shown?

What are the messages actually shown in dmesg when you connect the console?

cdsJerry

@stephenw10 I don't have a way to Copy/paste from that machine but here's a photo of the last lines.

I'm not familiar with screen.

cdsJerry

@stephenw10 Was that screen post any help?

stephenw10

Ok the screenshot looks as expected. Nothing wrong there.

@stephenw10 said in Can't access remote console:

I can then open ttyUSB0 with screen /dev/ttyUSB0 115200.
You may need to use sudo with that depending on your user.
To escape screen press ctl+a then k then answer y.

Try connecting to it with screen instead of putty as I showed.

Steve

stephenw10

Reviewing this whole thread it seems likely Putty is just not configured correctly on either Windows or Linux.
When you click Open and it does nothing or just the Windows error sound it pretty much has to be because it's trying to open something invalid or doesn't have all the settings necessary.

If screen doesn't work (I believe it will though) lets see some screenshots of your putty config.

Steve

cdsJerry

@stephenw10 Tried it with screen. I get an error message "Cannot exec '/dev/ttyUSB0' : No such file or directory

You said Putty probably isn't configured correctly but I've used Putty to access this same appliance in the past with the same computer (as well as the other four computers we've now also tried).

I agree that it's trying to open something invalid... because none of the programs is able to communicate with the 3100. It's being non-responsive which makes it invalid. Attached are images from Putty with both Windows and Linux

Windows putty.jpg Linux Putty.jpg

stephenw10

Ok when running screen you have to run it using this command:

screen /dev/ttyUSB0 115200

It looks like you just tried to run /dev/ttyUSB0 dircetly.

Those Putty screenshots show the serial console settings but not the actual session you're trying to open which will be ssh and nor serial by default.

Make sure you have set 'serial' in the session section at the top.

Steve

cdsJerry

@stephenw10 said in Can't access remote console:

screen /dev/ttyUSB0 115200

That IS the command I was running.

I have however gotten back into the remote console. I did another reboot and then use Putty on my original Windows machine and I got into the console. I have access again.

stephenw10

Ah, good news. Any idea what changed?

At least that shows the console port is good still.

Steve

cdsJerry

@stephenw10 I have no idea. Something in the reboot must have done the trick.

The computer was still up and running the same instance of Putty from my earlier tests. All I did was plug in the cable (because it had been plugged into the Linux computer), checked to make sure it was still COM3, and hit connect. I got a blank window (which did not happen before) hit enter a couple of times and was presented a # prompt.

stephenw10

Hmm, OK. Well glad you were able to connect.

The putty interface can be confusing at times. It's all too easy to think you're opening a serial connection when in fact it's just showing you the serial settings and the session is still set as SSH.

Steve