Programmable controller and control method thereof

Abstract

A 'programless' control method and an apparatus therefor which pre-stores the device numbers of input devices that are changed in response to the manual or external-controlled operation of a controlled object in accordance with a desired sequence control procedure. The results of the changes are stored in order in a transition condition storing table as transition conditions. Also, data input from external equipment and intended to be output to the controlled object as operation step data is pre-stored in an operation step storing table in correspondence with such transition conditions. Finally, in operation, the transition conditions are read from the transition condition storing table in storage order and they are compared with the current states of the input devices when the sequence control of the controlled object is executed. If any transition condition matches, the operation step data corresponding to said transition condition is read from the operation step storing table and is output to the controlled object. In this manner, programless sequence control can be exercised for the controlled object.