Issues with /dev/ttyUSB

Issues related to hardware problems
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ftotalcom
Posts: 1
Joined: 2016/01/29 12:42:55

Issues with /dev/ttyUSB

Post by ftotalcom » 2016/01/29 13:13:17

Hi im trying to connect to my Cisco Router Console Port (which is serial) from my Centos 6.7, Im using a USB to Serial cable to achieve it... More specifically this one:

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$ lsusb
Bus 004 Device 004: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter

I did the

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$ sudo modprobe usbserial vendor=1a86 product=7523 
And executing

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 $ dmesg | egrep --color 'ttyUS*'
. Displays:
usb 4-1: ch341-uart converter now attached to ttyUSB0

$ ls -al /dev/tty*|grep -i usb
crwxrwxrwx. 1 me me 188, 0 Jan 29 09:00 /dev/ttyUSB0


But after connecting to this device using different option it wont display anything on the session. I use putty and it would open the session but it only displays a black screen. Same happen using the package "screen" after

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sudo screen /dev/ttyUSB0
I double checked the serial speeds, bits and flow control values within a Windows PC that can connect to the Cisco Router

aks
Posts: 2538
Joined: 2014/09/20 11:22:14

Re: Issues with /dev/ttyUSB

Post by aks » 2016/01/29 20:42:38

I seem to recall that many Cisco routers don't use a null (or straight through) serial connection - could that be the problem?

Okiwan_Muskogee
Posts: 4
Joined: 2016/06/22 15:13:33

Re: Issues with /dev/ttyUSB

Post by Okiwan_Muskogee » 2016/06/22 18:37:37

Cisco routers use a "Rollover" cable to attach between a PC's rs-232 serial port and the devices Console port. This is NOT a Serial cable NOR a Null cable. Do a Google search for the differences.

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