Ladder-program managing device

Abstract

A ladder-program managing device includes: a database that has a ladder-program-storing region in which ladder program for individually controlling a plurality of pieces of machinery are stored, and that contains ladder-program-history information storing, in association with each other, identification information for identifying contents of alterations that have already been applied to the plurality of pieces of machinery and correction programs required to perform the alterations; and a database managing portion that manages the database, wherein the database managing portion is provided with an identification-information-searching portion that searches for, in the ladder-program-history information, identification information corresponding to an alteration content to be applied to an alteration-target machinery, and a merging portion that identifies the correction program corresponding to the searched identification information in the ladder-program-history information, and that merges the correction program with the ladder program for the alteration-target machinery.

Dependencies are inferred from the claim text.