> From: Aaron Jackson
> I have tried three controllers, two r/w modules and two servo
> controllers. I'm beginning to think the drive is fine and there is a
> problem with the RLV21 controller.
Err, think you mean RLV12 QBUS controller board, right?
Anyway, you've already tried ("three controllers") swapping that out?
If you have, perhaps there's a problem with a cable and/or the terminator?
However, at this point, sub-system swapping is probably not going to be the
best way to make progress. I think you're going to have to actually debug the
problem; i.e. dive in and work out what's happening wrong, and why, and trace
it back to the origin.
Luckily, for this generation (and before), DEC produced wonderful technical
manuals, which go into full detail of how the thing works. With that in hand,
the investigative process is a lot easier; you don't have to work out how the
thihg works by looking at the prints, it's all laid out in detail. And tech
manuals for both the RL02 drive and RLV12 controller (EK-RLV12-TD-001) are
available online, as are the prints (MP01282 for the RLV12).
So, I'd sit down with the RLV12 tech man and read through the section on the
drive<->controller bus (section 3.3). Then start looking at what the two are
saying to each other on the bus, and figure out what's actually going wrong.
>From there, you'll know where the source of the problem is, and can chase it
further.
I know this sounds like it would be time-consuming, but when you think about
the time/energy you've already put into swapping things around, chasing this
problem, it won't be.
Noel
