Analog Input records, Stream Device, and INVALID Alarms

[Dave Reid <dreid@u.washington.edu>]

I have a database that communicates via RS-232 to a vacuum gauge 
controller.  I do this by setting up an Analog In record, that has the 
DTYP set to "stream".   These Analog In records are part of a processing 
chain in the database.

What happens is that one of my AI records goes into the "Invalid" alarm 
state, and this breaks the processing chain, and the only way we have 
been able to recover from this is to reboot the IOC.

So the questions are:
1-Why are we getting into this alarm state?  Is this something that the 
stream device support is doing?
2-How does one recover gracefully from an "Invalid" alarm state?
3-Why is there not an "IVOA" field for input records?

Thanks....

dave