Two diagnostic models for PLC controlled flexible manufacturing Systems

The control of flexible manufacturing systems (FMS's) is generally characte rised by logical and sequential functions under the auspices of a programma ble logic controller (PLC). Operational faults associated with control proc esses are often confusing to maintenance personnel at workshop level. This has resulted in the development of automatic diagnosis techniques. In this paper two generic diagnostic models based on the logical function chart and sequential:control process of the PLC are developed. With the two compleme ntary models, the major operational faults of PLC controlled FMS's can be d iagnosed. Application of the models to a typical FMS is presented. (C) 1999 Elsevier Science;Ltd. All rights reserved.