Steps to troubleshoot serial ports on NodeGrid Serial Console

            1) Open ssh session and login as admin user

            2) Verify serial statistics of specific port: show system/serial_statistics/<port number>

            a) Example of port 7

            [admin@nodegrid /]# show system/serial_statistics/7

            7

            port: 7

            device name: cisco

            speed: 115200

            rx bytes: 33829054

            tx bytes: 165883

            rs-232 signals: RTS DTR

            cts shift: 1563

            dcd shift: 2520

            frame error: 0

            overrun: 0

            parity error: 0

            break: 260

            buffer overrun: 0

             

            b) ‘Rx bytes’ is not equal zero: target device sent chars to NodeGrid (unknown time)

             

            3) Reset serial statistics of specific port and confirm:

            a) cd systems/serial_statistics

            b) reset_statistics <port number>

            c) show <port number>

            d) Example for port 7:

            [admin@nodegrid /]# cd system/serial_statistics/

            [admin@nodegrid serial_statistics]# reset_statistics 7

            [admin@nodegrid serial_statistics]# show 7

            7

            port: 7

            device name: cisco

            speed: 115200

            rx bytes: 0

            tx bytes: 0

            rs-232 signals: RTS DTR

            cts shift: 0

            dcd shift: 0

            frame error: 0

            overrun: 0

            parity error: 0

            break: 0

            buffer overrun: 0

             

            4) Disable specific managed device, and commit

            a) set /settings/devices/<device_name>/access/ mode=disabled

            b) commit

            c) Example for device ‘cisco’ (that is in serial port number 7 as showed in serial-statistics)

            [admin@nodegrid /]# set settings/devices/cisco/access/ mode=disabled

            [+admin@nodegrid /]# commit

             

            5) Open another session to NodeGrid and log-in as root

            a) Launch ‘microcom’ at shell prompt that opens communication with the serial port:

            microcom -s <speed> /dev/ttyS<port_number>

            b) Try to communicate with device (to close microcom type Ctrl-X)

            c) Example for port number 7 - speed 115200 (as showed in serial statistics)

            root@nodegrid:~# microcom -s 115200 /dev/ttyS7

            cisco login:

             

            NOTE: If output shows garbage, stop microcosm (Ctrl-X) and try again with different speed.


            6) Verify port serial statistics in admin session (step 2)

            a)  show system/serial_statistics/<port number>

            b) Example for port 7 - no problem (rx bytes not equal 0 and there is no error)

            [admin@nodegrid /]# show /system/serial_statistics/7

            7

            port: 7

            device name: cisco

            speed: 115200

            rx bytes: 282

            tx bytes: 5

            rs-232 signals: RTS CTS DTR DSR CD

            cts shift: 3

            dcd shift: 2

            frame error: 0

            overrun: 0

            parity error: 0

            break: 0

            buffer overrun: 0

             

            7) Enable specific managed device after, and commit

            a) set /settings/devices/<device_name>/access/ mode=enabled

            b) commit

            c) Example for device ‘cisco’ (that is in serial port number 7 as showed in serial-statistics)

            [admin@nodegrid /]# set settings/devices/cisco/access/ mode=enabled

            [+admin@nodegrid /]# commit

             


             

            Results:

            1. If serial statistics shows CTS, DSR or CD signals, a device is connected and it is on.
            If none of these signals are shown, there may be a device connected that does not implement all RS232 signals. This is common in some network switches.

            2. If there is no output when executing microcom and the statistics shows 0 rx-bytes and no errors:
            - the cable is wrong, or
            - the target device is off, or
            - there is no device connected.

            3. Errors (including buffer overrun) indicates a mismatch in the serial port config (i.e. parity, data bits, stop bits).



            Updated: 11 Jul 2017 01:59 AM
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