Machine Status Link Panel

[nda@aps.anl.gov (Ned Arnold)]

Dean Haeffner forwarded comments to me about the prototype machine status
panel. Two of the requested changes (a true signal for beam currents > 1mA
and a 'beam ready' status) have already been made in the prototype
units by changing a programmable logic device. The third request (packaging
the fiber video receiver within the same chassis) will be incorporated in the
next batch of panels, hopefully available in ~ 4-5 weeks.

With the above changes, the panels indicate three statuses from the 
accelerator. 

Not Injecting - LED is GREEN when NOT Injecting, RED while injecting

I > 1 mA      - LED is GREEN when I > 1 mA, RED when I < 1 mA

Beam OK       - LED is GREEN when beam is 'usable', RED when it is not. 
                The initial implementation of 'usable beam' is simply
                echoing the 'Shutter Permit Status'. A more concise
                derivation of 'usable beam' will evolve later.

Each status has a TTL signal available as well. GREEN is a TTL HIGH, RED is
LOW.                

The above implementation provides for ALL GREEN LED's when there is usable
beam in the storage ring that exceeds 1 mA. This seems consistent from a 
user's perspective.

Thanks for your comments, and I am certainly open to further input and
additional features that you may determine as useful.


	Ned