Programmable control device for controlling e.g. display device, has microprocessor finding ratio of number of components of input and output circuits in switch-on state, where circuit evaluation is performed based on average value

摘要

The device (1) has a microprocessor (5) for controlling output signals, which work responding to a sequence program stored in a memory (4) base on an input signal used in an input circuit (2). The microprocessor finds a ratio of number of components of the input circuit and an output circuit (3) in a switch-on state relative to number of all components in a constant period. An average value of the ratio simultaneously finds the switch-on state in a preset time period. A circuit evaluation is performed based on the average value.