Abstract:
An on-line diagnostic system is provided working conjointly with but not interfering with the operation of a logically controlled industrial control system. Thus binary digital words are displayed at a centralized location for comparison with a scroll chart to indicate irregularities of operations by listing invalid words and to pinpoint correctional techniques with a predetermined servicing recommendation for invalid word combinations. In a preferred embodiment the system is a fluid controlled binary operated cyclic control system provided with logic elements interconnected for automatically progressing through a cyclic operation mode controlling flow paths for working fluid under pressure in a desired sequence to thereby perform a work function. The preferred fluid logic elements comprise a compartment separated into two chambers by a flexible diaphragm which is flexed by pressure differentials to block or open fluid flow paths through the respective chambers. Binary indications as to status of these flow paths are provided as pressure readings at a plurality of key flow path positions thereby producing the binary word information specifying the nature of malfunctions.
Abstract:
Fluid back-pressure flowing out a cylinder when being powered through a stroke is sensed by fluid logic circuits to produce a signal which indicates that piston movement is slowed or stopped. A fluid logic device with a flexible impervious diaphragm senses the back pressure to provide an output signal when the piston is not functioning properly. The detector is made more sensitive and selective by restricting a flow path for the back-pressure and operating the logic device as a pressure amplifier, responsive to a threshold back-pressure valve. The sensor is operable to produce a negative going dynamic output transition as a signal that the piston rate is not exceeding a particular threshold value.
Abstract:
Pulse actuated binary fluid responsive logic elements are connected in a control system for a fluid flow network operating a fluid responsive mechanism. The logic elements are interconnected to respond to a trigger pulse and automatically sequence through a cycle of operation sensing and responding to fluid pressure conditions at control points in the flow network. A portion of the control points are monitored with diagnostic binary pressure indicators to indicate the status of the network during the control sequence by display of binary words. For correcting malfunctions a comparison chart indicates the nature of invalid words and the corresponding procedure for correcting the malfunctions sensing that word structure, thereby expediting servicing by semi-skilled personnel without detailed knowledge of the system operation.