  There are six service buildings uniformly spaced along the perimeter of
  MI (Main Injector). A total of 18 LCW pumps were installed around the MI ring
with 3 pumps per building. Approximately 8,000 GPM of LCW is required to cool
magnets, bus and power supplies in the MI enclosure and service buildings. In
each service building, a PLC control system controls pumps and valves, and it
monitors pressures, flow, resistivities and temperatures. The PLC hardware
system consists of a Gateway module and a variety of I/O modules, which are
made by Sixnet of Clifton Park, NY. The control system communicates with other
buildings including MCR (Main Control Room) via an Ethernet link and front-end
computers. For more details of the MI LCW control system, refer to [1] and [2].
One of the key elements of the PLC software is called ISaGRAF workbench, which
was created by CJ International of Seyssins, France. The workbench provides a
comprehensive control-programming environment, where control programs can be
written in five different languages. For more details of ISaGRAF, refer to [3].
