Typically the control architecture of a flexible manufacturing system (FMS), as part of an integrated manufacturing system (IMS), consists of a hierarchical structure of computers, most with differing duties and some with differing responsibility. At the lowest levels of the hierarchy are the FMS work stations or subsystems (machine tools, material handling system, chip handling system, etc.) and above that the FMS control computer (the host) with the general overseeing or management responsibility. The proper functioning of this control hierarchy requires the intercommunication of commands and data between the FMS control computer and the FMS subsystems. The controllers and computers used in FMSs are, however, manufactured by a number of different companies most, if not all, of which employ unique hardware plugs and electrical signal structures for communication of data from machine to machine. It is by way of this discussion that the need to develop and implement an FMS communication standard is justified.
The approach we have taken (and an outline for the paper) includes: (1) a survey of the difficulties in FMS intercommunication, (2) establishing the data that are likely to be transmitted within the FMS, (3) setting forth the framework for a communication standard that addresses points 1 and 2, and (4) describing current FMS industry efforts to design an FMS intercommunication standard.