Exphi provides exposure and exposure shutter synchronization with a Phi
rotation axis.  Both the digital I/O points and the rotation axis are assumed
to be controlled by a Delta Tau Turbo PMAC controller (e.g. Delta Tau Turbo
PMAC Clipper).  Part of this software is implemented as a PLC program that
runs on the PMAC.  The other part is an EPICS interface allowing control from
EPICS.

Written in July 2009 by J. Lewis Muir <jlmuir@anl.gov> (IMCA-CAT).
