tty keeps locking

[dvokins]

System running SCO 3.2v4.2 has 16 serial devices, one of these ports keeps getting an administrative lock on it. I go into sysadmsh and it says that there was 198 failed login attempts. There is no one sitting at this terminal trying to get in...I know this for a fact. Does anyone have any idea what would be causing SCO to think that this terminal is failing on login attemtps?

Thanks Doug Vokins
Systems Analyst/Programmer
General Computer Systems

 

[pcunix]

Defective terminal or defective serial port. Bad wiring could also do this.

Swap the terminal with another one, see where the problem goes. If it stays there, is your wiring setup such that you can swap the wires on two ports? If not, you need to look at voltage levels on the wire- see

http://pcunix.com/Unixart/serial.html

Depending on what you actually have, you may have a utility that will help you look at the multiport hardware- for example, Digi's "mpi" will let you examine signals onm the ports, see whether data is flowing etc.

Also check "fuser /dev/tty???" - you may have extraneous processes running here that are screwing you up. Tony Lawrence
SCO Unix/Linux Resources

http://pcunix.com

tony@pcunix.com

 

[edfair]

One possible diagnostic is to temoorarily disconnect the terminal at the unix box, then jumper transmit and receive for both the unix and the terminal (pins 2 & 3) for a while.Problem can be line driver in the termianl or line receiver in the multiport, or it can be the wiring, either noise or possibly open common. then wait a decent time and see what has happened. If the terminal gets garbage you need to do the turnabout at the terminal itself.
If you have some flow control active you may need to add some other jumpers to let transmit and receive get through. Ed Fair
unixstuff@juno.com
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.