Abstract :
Data acquisition and control systems have often included the need for high throughput between the "front-end" hardware and the host computer. This is particularly true in the aerospace/defense and experimental physics fields. With the advent of more sophisticated I/O hardware and faster host computers with larger memories, the need for higher performance real-time computer interfaces has increased dramatically. A family of CAMAC-based interface products has been developed that supports high data throughput while providing the flexibility to meet the particular application. These new products fall into three basic categories: enhancements to the CAMAC Serial Highway, new CAMAC crate controllers, and software drivers. The Serial Highway enhancements provide at least a five-fold improvement in effective throughput and rival the Parallel Branch Highway in that regard. A new crate controller with a ribbon-cable bus interface uses balanced-line transmission and supports a bus length to 500 feet. List processing is provided as a hardware option for the Serial Highway Driver and is supported by a list sequencer module, an auxiliary crate controller, as well as software device drivers. This paper describes these new products, details their performance, and recommends trade-offs for their application. Benchmark comparisons indicate the extremely high data throughput that has been obtained. With certain configurations, Serial Highway throughput approaching three megabytes per second can be achieved.
