16-port adapter problems with ports 0 to 7th.
ITEM: RTA000070443
I have a 7011-230 with 2 RS-232 16-port adapters and after configuring
a tty for each port, the ttys from port 0 to port 7 didn't work.
Each port from 0 to 7th, displayed at the terminal the AIX login prompt,
but if I press ENTER, the port hangs and doesn't work any more.
I checked the following, to ensure proper configuration and
hardware components:
. port baud rate, parity, stop-bits, handshake protocol
. cabling between the terminal and multiport
. terminal's configuration (same as port baud rate, parity, etc.)
All this stuff was OK, so, I tried many things such as:
. Another terminal (properly configured)
. Another cable that was working well from port 8 to 15 of the
same adapter
. Another multiport interface cable
. A new RS-232 16-port adapter
. Re-installed the AIX operating system and re-configured a tty
for each port
. Change the micro-channel raiser card on the planar of the 7011-230
. Change the 7011-230's planar
As you will see, practically speaking, I tried everything, and
the ports from 0 to 7 still didn't work.
Ports from 8 to 15 worked very well, even with the same cables
and terminals used in the ports 0 to 7.
I'm experiencing this problem
in both 16-port adapters installed in this machine.
ANSWER
I have a few suggestions which may help to isolate the problem.
1) Check the stty values of the ports 0 to 7 against the working
ports 8 to 15. Use the "stty -a < /dev/tty#" command.
Look for discrepancies in the output. In particular, make
sure that the "cread" is enabled.
2) Make sure that login is enabled, "penable tty#".
3) Are there any applications running which may be changing the
stty attributes for ports 0 to 7?
4) Did the ports 0 to 7 work at any time in the past? If so, then
what has changed on the system since the last time they worked
(i.e. system crash, configuration changes, applications added,
etc.)?
5) Is the terminal a supported terminal? Are you using any
terminal emulations? Could terminal communications settings
be incorrect (check on both the terminal Hardware set-up and
SMIT)? Compare settings with a working terminal on ports 8 to
15.
6) Which AIX level are you running?
7) What processes are running on the tty (use "ps -ef|grep tty#")?
8) Can you cat to the tty (i.e. "cat hello > /dev/tty#")?
If not, what are the results of this command? Please include
any error messages.
9) Are you using supported cabling on these ports? Or, are
custom cables being used? You may wish to check the RISC
System/6000 System Overview (GC23-2406-03) for additional
information on supported cabling, and pin-out information
if custom cables are being used.
10) Make sure that your cables are not running by power supplies,
florescent lighting, or through walls.
11) You may wish to try setting "clocal" to on in your RUNTIME and
LOGIN for a tty on ports 0 to 7. The stty clocal attribute
is normally off. Setting the clocal attribute will make the
RISC System/6000 ignore carrier detect (CD). It will assume
that the terminal is always there, always on. The system
will ignore any power offs to the terminal. In some instances
you can loose data. But, this test may help in determining if
cabling or terminal set-up is the problem. If this does not
help, reset the stty values to -clocal.
12) You should make sure that the 16-port adapters are firmly
seated in the microchannel slot. Also, you may wish to try
running diagnostics on the affected hardware. Or get a
Customer Engineer to to check out the hardware.
S e a r c h - k e y w o r d s:
16-PORT TTY HANG
WWQA: ITEM: RTA000070443 ITEM: RTA000070443
Dated: 05/1996 Category: ITSAI6000HW
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