Method and apparatus for displaying ladder diagrams.

摘要

An apparatus for displaying a ladder diagram in a numerical control system having a programmable sequence controller function in which sequence processing is executed based on a sequence program to deliver commands from a numerical control device to a machine and signals from the machine to the numerical control device. A display unit (CRT) displays the sequence program in ladder diagram form made up of at least relays. The identification of a relay (M03) or the memory address storing the state of the relay (M03) is entered by means of an input device, and an item of sequence data employing the relay (M03) is selected based on the relay identification or on the memory address. A segment or rung of a ladder diagram that is based on the sequence data and thereby employs the relay (M03), is then displayed on the display unit (CRT).