Conveying system control

Abstract

A control scheme is used in a conveying system which is preferably a programmable conveying system of the station searching type including a wagon with a hoist that is capable of traveling between a number of different stations in the system. One or more of the stations has the control which in the disclosed embodiment is a rectifier setting control associated with a tank at a station. At the time that the piece being conveyed is loaded at a load position, the operator introduces a coded card or the like carried by the hoist, which card may be subsequently read by a reader with the data on the card representative of a particular rectifier setting. This data in a binary form is conveyed by a multiple bit data bus to a digital to analog converter. If the system includes a plurality of stations to be controlled then the data is coupled to all digital to analog converters. The control further provides means for selectively enabling only one of the converters depending upon the attitude of the hoist and the location of the hoist. Thus, when the hoist is at the proper tank, data from the card or other indicia is read and the converter is enabled to thereby provide an analog output control signal for controlling the rectifier associated with the tank to in turn control a process such as an electroplating process.