  External contractors are developing the local cooling and vacuum control
systems for the Spallation Neutron Source (SNS) linac. Soon these systems will
be integrated into the facility-wide controls system. Allen-Bradley Logix5000
series programmable controllers, populated with appropriate input/output
modules, were selected as the local controllers. These controllers will be
interfaced to the facility-wide control system via VME systems with PowerPC
processors running the Wind River VxWorks operating system and Experimental
Physics and Industrial Control System (EPICS) front-end controller software.
This paper describes the interface and integration issues driven by project,
cooling system and vacuum system requirements and hardware selections.
