Accubeat AR-40a information, manual, experience?

[Cyclotron]

I just acquired an Accubeat AR-40A rubidium frequency standard. I've been looking for information about it, the lock output nature, the serial interface settings and command reference. Anything really.  I'm hoping someone has some experience and information on the oscillator.
Thanks

[Cyclotron]

So I contacted Accubeat and they provided this manual. I was hoping for more information on the serial communications but I'm extraordinarily happy with the fact that they responded at all. To me, this is a sign of a great company.  This oscillator is 2 generations old and no longer on the market for sale. I'm simply asking for information for study and my own research and use and they provided it on a weekend.

I'll certainly be considering their products for my projects when I need new components.

[Cyclotron]

Image of side 1 of board.

[Cyclotron]

Oscillators mounted in this picture.

[Cyclotron]

Other side of board.

[Cyclotron]

As it stands, this unit does not appear to achieve lock.  I have tested the output on the "BITs" pin for short to ground when locked and I do not see that happening.  If someone is familiar with these and knows of a failure mode that is common, I'm very interested.