By Gino Crispieri, ISMI, Texas

ABSTRACT

Timing requirements placed on maunfacturing systems are becoing increasingly stringent in the semiconductor industry.  Traditionally, these manufacturing systems have been implemented in a centralized architecture in which the timing constraints were met by paying careful attention to programming combined with the use of communication technologies with deterministic latency.

In recent years, an increasing number of manufacturing systems have used distributed computer architectures and relied on mainstream networking technologies.  In particular, Ethernet-based communications are becoming more common in manufacturing applications.  This has led to alternative means for enforcing the timing requirements in such systems.  One such technique is the use of system components that contain real-time clocks, all of which are synchronized to each other within the networked system.