# Another serial-usb adapter thread



## Ishamael (Aug 25, 2012)

Hi everyone, 

I have a freeBSD 8.1 box which has a usb serial adapter connected for access to a network switch's console. When you connect the adapter it shows up under dmesg(8) first under ugen and after under uplcom0. 
The new device shows up as /dev/cuaU0 ok. But when I try to use 

[cmd=]cu -l /dev/cuaU0 -s 115200[/cmd]

to connect is just says connected and freezes. From the switch guide it states the conn should be ANSI emulated 8n1 115200 bauds with no hardware flow control, but besides the speed I'm not sure how to configure the rest. Any help?

Thanks!


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## wblock@ (Aug 25, 2012)

Does it need a null modem (crossover) cable?  Some ports expect DTR or other signals to be a certain way.


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## Ishamael (Aug 26, 2012)

Thanks for the reply. Sorry I wasn't more informative on my first post. The adapter's connected to a crossover cable, which I've tested on linux and windows boxes and works fine. 

Could you tell me how to play around with how its going to send the dtr signal you mentioned?


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## wblock@ (Aug 26, 2012)

Usually that is done with the wiring of the cable.  However, since your cable has been proven with other operating systems, it's okay.

115200 baud is ridiculously fast for a serial device, and for that it seems like hardware flow control would be useful.  Because it's easy to test, I would press ctrl-Q after starting cu(1) just in case it has already sent a ctrl-S.  Also easy to try is 9600 baud, but if 115200 worked on the other systems...

There are variables for flow control in cu(1), but hf is supposed to default to off.

Beyond that, a serial break-out box with LEDs to indicate the signals could help show what FreeBSD is doing differently.


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## SirDice (Aug 27, 2012)

Most serial (console) ports on routers and switches use 9600 baud, 8 bits, 1 stop bit, no parity.


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## tingo (Aug 28, 2012)

Also, check out stty(1) for changing parameters.


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## Ishamael (Aug 29, 2012)

Hi everyone and thanks for the posts. I've been doing some playing around and the problem I found is that the port actually connects to the console and sends ok, but it never displays the remote side (I can log in and change things, but doing it blind). The speed for this device is 115200, and I can actually change it through the device's config. I tried setting it to 9600 on the device and in cu with the same results. 
I'll look at stty to see what I can do from there, in the meantime any suggestions are very welcome. 

Again thanks for everyone's input.


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## SirDice (Aug 29, 2012)

If it doesn't "echo" anything, i.e. you're typing blind, turn on local echo. 

comms/minicom might be a little easier to use, especially if you know the old MS-DOS Telix application.


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## wblock@ (Aug 29, 2012)

I read that as the opposite: local characters typed are seen, but nothing from the other system.  No idea what would cause that.  Enabling local echo or half duplex solves the opposite problem, local characters not being shown because the local system expects the remote to echo them back.


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