Protocol Toolkits for Distributed Real-Time Experimental Workstations

An experimental workstation is often an end system in a network of systems generating, processing, and presenting data. Graphic software standards for workstations often extend the virtual display device model but leave little flexibility for application programs using task and process concurrency in all systems, including the workstation. Such applications are true distributed systems; they benefit from use of standard services in communications facilities, and from formal methods of design and implementation for custom protocols, where standard services are inadequate or non-existent.As an example, a protocol for synchronization of clocks by exchange of timebase messages (based on an existing network timestamp protocol) is generalized to a method for tracking and synchronization of other real-time databases, which can be applied to distributed interactive world-coordinate clipping of a real-time data stream for graphic display. This method of distributed clipping is illustrated in a system for interactive display of real-time weather data.