INTRODUCTION
The success of the SNS is measured by the high availability of all systems during operation including vacuum subsystems and their components. Beam energy increases as it progress through from the ion source to final delivery of the beam on the target with vacuum operating levels varying to support physics requirements. (see table 1) [1]. The design of the SNS vacuum system and its control system has been achieved through a multi-laboratory collaboration. To maintain the necessary high reliability, availability and flexibility of the vacuum system, both Programmable Logic Controllers (PLCs) and EPICS Input and Output Controllers (IOCs) are used for controlling and monitoring the vacuum devices except for the superconducting vacuum control system that required a fast response time for the sector gate valves (SGVs) [6]. Although a great deal of effort has been taken to standardize vacuum instrumentation, components and global control system interfaces [2], two major challenges had to be overcome for the successful integration of the individual vacuum control systems delivered by different partner labs.