Experimental Physics and
Industrial Control System

[email protected] · Thu, 14 Nov 1996 13:10:05 -0500 (EST)

Hello all,

	We are starting a major upgrade of our RF transmitter controls
which will use EPICS.  We would like to find out how other Labs are
controlling devices in this type of environment:

1. Lots of pulsed noise.

2. Signals and Controls physically near crowbars circuits which produce 
   a LARGE ground bounce and EMI.  (A crowbar causes the 150KV 2uF cap bank 
   to be shorted to ground causing a 20,000 amp short in 5 ~usec.)

3. Signals which originate in the Modulator Deck which floats at 150KV in oil.
   There are a large number of signals originating in the deck so we would
   prefer to have intelligent monitors in the decks verses many optic fibers
   coming out of the deck to ground.

4. Signals in the mod deck can be subjected to high voltage transients such
   as 100V, 2.5KV, and 19.5KV.  

Should the IOC's be located near the transmitters?  What are the experiences
at other Labs with the reliability of the IOC's near high power pulsed
sources?

What type of field buses can handle this type of environment?  We are
considering both PLC's and CAN Bus.

Do other Labs run local buses to high voltage potentials, in oil, and
if so, how is the reliability of these modules after fault conditions?

Are commercial digital IO and Analog Input modules available with high
transient protection? 

Thanks in advance for any comments, suggestions, etc.

Coles Sibley
MIT Bates Linear Accelerator Center
21 Manning Rd.
Middleton MA 01949
617-253-9518

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System