In recent years, great interest has developed in the possibilities for using computer vision systems in a variety of industrial applications. These range from complex inspection or monitoring tasks to supplying precise position and orientation information for part feeders or robotic manipulators. The paper describes the work being done at the GEC Hirst Research Centre to develop a modular vision system with its own structured interpretive language. Such a system will provide an excellent tool for building and programming industrial vision systems. The vision system has been incorporated into a robot workcell, and an experiment is described which demonstrates the use of several co-operating processors to perform a simple assembly task