Using remote access port for connecting serial devices

[Natesan_1]

Sunil / Syam,

Thanks for your reply.

I Hope you don't understand my question.Please stop replying unwanted information repeatedly.

[Sameer_Nirmal]

Hi,

If I understand your question correctly, the customer wants to use the Remote/Modem port at the back of the server for using a serial terminal.

Well , it is not possible to use a Serial terminal ( pins 2,3 and 7 or 5 i.e. without any handshaking ) directly with this port because this port specifically programmed to use with an external modem. The reason is the way the firmware is programmed which check the status of status signals ( DCD , CTS etc ) and controls signals ( DTR , RTS etc). If you attach a modem there and set appropriatly , you can dial-in and get a OS session if selected mode is " OS session". Of course , you need to do configuration in OS for get the session. If the mode is " Management" then access to this port is available from MP only.

Well I haven't try this ever , the trick involved could be using a Null modem cable with various handshaking techniques for DTE/DTE communication. But again we are not aware how the firmware is programmed and how it works. Maybe one of the handshaking technique would work.
But I would advise to contact HP support center and get the correct supported technique. If it works then you can create a device file in OS OE and get an OS session on that port similar procedure as if modem is connected on that port.

[Natesan_1]

Hi Sameer,

Your understanding is correct.Device which we would like to connect maynot be terminal, it is serial com device.First we would like to test by configuring device file.

I will try to use device file /dev/tty1t4 for accessing remote access port and enabling SE on remote access. I will seek, HP assistance in case of problem.

Thanks for your prompt information.

[Natesan_1]

The device file /dev/tty1p4

[Sameer_Nirmal]

Hi Natesan,

You are trying to use the local sesion port /dev/tty1p4 for estabilishing an OS local session ( note: it is not a console session )
I guess you can only use it if you are directly connected to Local or Remote Console ports i.e MP -> SE
As you are trying to use the Remote port, you have to have a serial device connected to that port which will give you console access first( console session ). Then you can go to MP and use SE command to use the OS session created with the device file.

The device file for the Remote/Modem port is /dev/tty1p2 which gives you Remote Console access once you dial-in.

[Stefan Stechemesser]

Hi Natesan,

although HP does not support it, it should work when the modem port is configured to "OS session".
I just successfully configured our rp3440 running HPUX 11.23 (MP firmware 3.15) to show a logon prompt on a remote terminal connected to the remote modem port (9600 baud, 8 bits, no stop bit) by using the default device file /dev/tty1p2 and inserting the following line in /etc/inittab

t1p2:234:respawn:/usr/sbin/getty -h tty1p2 console 9600

then "init q" to make the changes active.
You can also use /dev/tty1p2 for outgoing serial traffic to your device.
To set or view the serial line settings (if you are not using getty) use

stty -a < /dev/tty1p2
and of cause: "man stty"
also interesting:
"man mksf" (then search for the options for asio driver)
"man modem" (for deeper info on modem control lines)


Unfortunately, there is a little bug in the firmware: After a reboot, the Remote Modemport always falls back to "GSP mode" (but still OS session will be displayed) if it was in OS session mode before.
=> you have to manually lock and reenable OS session mode after each reboot.
This bug will be fixed in future versions of the MP firmware.

By the way, the devicefile for the UPS port is /dev/tty0p0. I tested to set up a getty on this port too, and I got a login prompt. Unfortunately another application or the MP also wrote garbage to that port when I logged in and I could not investigate the source of that problem. Maybe you have more luck ...

best regards

Stefan