A ladder diagram monitoring device displays an operation situation of a ladder program executed on a programmable controller built in a CNC on a monitor. A comment added to a circuit of the ladder program is provided with a region for displaying information on an operation situation of the CNC, the operation situation of the ladder program is reflected in the region, and display data in which the operation situation of the CNC is displayed is displayed.

A numerical controller includes a programmable controller that performs input and output of a signal based on a ladder program and performs control of a machine based on an NC program. The numerical controller includes a first table associating the function used for control of the machine, an input signal, and an output signal and a second table associating the input signal, the output signal, and a signal in a dependent relation with the input signal and the output signal. Based on a function code of a function commanded by a block of the NC program that is preread, the numerical controller refers to the first and the second tables, identifies a signal to be subjected to automatic trace, and performs trace.

The invention relates to a method for controlling an automated work cell (2) including at least one robot arm (4) with at least three degrees of freedom (A1-A6), a programmable logic controller (6) suitable for developing a trajectory order (Om) based on an instruction to perform a trajectory of an application programmed in the programmable logic controller, a robot controller (10), suitable for steering the movement of the robot arm (4), and a communication bus (5) between the programmable logic controller (6) and the robot controller (10). The method comprises steps consisting of a) developing, in the programmable logic controller (6), a trajectory order (Om) including parameters for executing a trajectory defined at least between a departure point and an arrival point; b) transmitting the trajectory order (Om) developed in step a) to a computing unit (11) of the robot (10); c) developing, in the computing unit (11) of the robot controller (10) and based on the trajectory order (Om) transmitted in step b), elementary movement instructions for steering the robot arm (4) on the trajectory defined by the trajectory order (Om).