Mux port issues

[Jim Lynn_1]

We have a G30 running HPUX 10.20 that has RS422 muxes hanging off them with time clocks plugged into them. Is there any way to trouble shoot the mux ports??
We are looking at replacing them with terminal servers - but we don't really know whats plugged in, there are some things that were removed that still are cabled. Is there anyway to watch what going on with the ports?

[Mark Greene_1]

You can use SAM (peripheral devices/terminals and modems) to get the tty info on the ports. You can then grep ps for the tty's to find out what processes are attached.

mark

[blal]

Hi

For testing you can connect any dump terminal and observe for some time.


You can measure the voltages of 2,3,6 pins and see proper voltage levels are appearing.

One important thing is proper erthing should be there for all the devices attached to this MUX ports.If any floating voltage is there between Earth and neutral then , hanging problem is obeserved in connected devices.

regds,
baiju

[doug mielke]

iostat -t might help.

I haven't tryed with anything like a clock, but I've found terminals with something like

cat whereareyoufile > /dev/ttyxxx

asking in the message to call when this diplays or prints.

[Darren Prior]

Hi,

An ioscan -funCtty will show you the different muxes that you have and their device files. You can then run fuser against each device file (remember that it's possible to have more than one device file per port, eg if someone has created a modem then you would have ttyd, tty, cul and cua device files.)

Fuser will show you a process id (if any) that's using the port, you can then use ps -ef | grep to find the command used.

regards,

Darren.