Programmable controller for synchronously tracing the execution of operation blocks and SFC program execution method using the programmable controller

Abstract

The present invention provides a programmable controller for executing an SFC program. The programmable controller has a memory which stores a step trace program for storing and tracing a history of execution statuses of active steps of a plurality of blocks of an SFC during execution of the SFC program. The step trace program comprises a step trace setting subprogram which, through the use of a peripheral device, synchronously traces the execution statuses of the active steps of the plurality of blocks. The step trace program further comprises a step trace execution subprogram which creates step trace data based on the execution statuses of active steps traced by the step trace setting device. The programmable controller further comprises a step trace display device for displaying the step trace data. Hence, an operator can simultaneously view the execution status of active steps of a plurality of blocks of the SFC to thereby determine which active steps have been executed at any given time.

Dependencies are inferred from the claim text.