Hierarchical multi-level computer network for laboratory automation

The design and implementation of a microcomputer network to support laboratory automation is described and discussed. It is a multi-level hierarchical star network connected to a multiprogrammed computer on which all program development is done. The system is capable of supporting a large number of experimental setups. The microcomputers are either used as (1) local microcomputers for experiment control, (2) multiplexers for other microcomputers or (3) controllers for peripherals known in the multiprogrammed computer. The system combines the advantages of a large multiprogrammed computer with those of a small cheap dedicated computer close to the experiment. Character-oriented peripherals are connected to the multiprogrammed computer only. This reduces the amount of system software to be written for the network by an order of magnitude and eliminates the need for interfacing to existing small computer software. The system software consist of three small programs (monitors) providing a process concept and multibuffering of data in the involved computers. The monitor establishes a hierarchy of control and they eliminate the need for any local load device for the microcomputers as their monitors are in a read-only store. The system developed is designed for control of experiments in an environment where the experiments and the control strategies change with time and where the data refinement required is beyond what can be done on the present generation of microcomputers.