[time-nuts] Austron 2110 GPIB - update

[Skip Withrow]

Hello Time-Nuts,
It was a long, painful process - but I finally got the Austron 2110
GPIB working.  I learned a lot that is not documented in the manual
that I have, so here is some information if anyone ever tries to
operate GPIB on this unit.

1. The firmware matters.  I have both version 'F' and version 'K' of
the firmware.  Version 'F' knows nothing about GPIB.  I don't know if
there are versions intermediate to the ones that I have, but version
'K' does have the GPIB interface software incorporated.

The GPIB is controlled by the SS1 key on the front panel.  This is
documented nowhere in my manual, even though my manual has several
pages on the GPIB syntax and commands, with examples.
SS1 - 1 allows each of the commands to be individually turned off or
on in Talk Only mode.
SS1 - 2 allows you to examine the configuration of the GPIB interface
(GPIB address, SRQ setting, Talk Only setting).
SS1 - 3 allows you to reset the GPIB interface.

BTW - My manual indicates that the SS0 key displays the startup
screen, in addition, it can also be used to lock out the front panel
keyboard (this is not documented in my manual).

2. The MC68488 controller chip matters.  There were two mask sets for
this part, the early mask set with 'GG' before the date code DOES NOT
WORK.  The chip that I have working has the 'P9W' before the date
code. (it took me a while to find that one)

3. There are undocumented GPIB commands that are not in my manual.
They are FMIO, FMIX, NSTA, IMDE, TRGT, TPHI, and TIME.  TIME is pretty
obvious, and I have not investigated the others yet.

If anyone has a manual with this information included I would love to
get a copy (of just the GPIB section if nothing else).

The Austron 2110 is a neat unit, it basically is a cleanup oscillator
with a 100sec time constant, my only complaint is that the DAC
resolution is only 1E10-12.  However, there is an option (which both
of mine have) for dual inputs (either 1, 5, or 10 MHz) that are
statistically combined to discipline the oscillator in the unit.

If you have one, working or not, that you want to get rid of please
contact me (off list).

Regards,
Skip Withrow