Twinax wiring question - pigtails
Matt Carpenter
I am tinkering around with a pretty old AS/400 (9402-2xx). I have a problem
getting my terminal (InfoWindow 3488) to talk to the machine. I think it's
the twinax wiring. The terminal has a female DB15 connector as does the
twinax pigtail. So, I've tried a DB15 gender changer. I've confirmed that
the signal order on the pins is preserved.
Does anyone know if there's a difference between the Twinax self terminating
T - DB15 female pigtail and the DB15 male version?
Here's my setup:
1. AS/400 to twinax terminating block
2. Twinax cable from block position "0" to self terminating T pigtail
3. pigtail DB15 female connector to a DB15 male-male gender changer
4. gender changer to IBM Infowindow II (3488-V) terminal - the DB15 female
port
When I fire everything up, the terminal just sits at a blank screen (cyan
baseline with "1/80") in the lower right hand corner.
The AS/400 boots up with A6005004 on the hex display. I press keys on the
terminal and nothing happens.
I think that I simply have the wrong pigtail. Is this correct?
-Matt
Richard Knowley
pigtails that work on one terminal but not on another. So it's
certainly possible that the ones with female connectors use different
pins and/or polarity than the male ones.
The 1/80 at the bottom of the display is the cursor position (row 1
column 80). Most IBM 5250 type terminals (and even most of the
emulators I've seen) will leave the cursor in the upper right corner
of the screen (where yours is) if there is no line sync with the
twinax controller. If you have line sync, but a bad device address
setting or configuration, the cursor will generally jump to the upper
left hand corner (this would be 1/1 on your display). And if
everything is ok then (of course) you get a sign-on screen.
So we know you don't have line sync. And if the terminal itself is
good, then that usually means the 400, the cable, or the pigtail is
bad.
Assuming the 400 and the cable are ok, it could be a bad terminal.
But without the known correct pigtail, it's going to hard to test.
You can run the setup program on the terminal and that will usually
tell you if the logic board is ok. If I recall, on those terminals
you power off, then hold down the reset key while powering up the
terminal to get into setup. But I've seen terminals that run setup
and diagnostics ok but which still wont sync up.
And while you're in the setup program, make sure the address (for at
least one of the sessions) is set to 0 (zero). A bad address here
usually won't keep the cursor in the upper right, but if you do get
line sync by replacing the pigtail, you'll want to be set as the
system console, which is always port 0, address 0.
I think I have a couple of dead Infowindow terminals at my office, and
I may have a spare pigtail. If you're interested, email me and I'll
check. If I've still got one, you're welcome to it.
Richard Knowley
Klein Allen Company