Introduction

The command variables required for a machine motion are generated within a channel. In this case, input information which may be an instruction from an NC program, a manual motion block or an incremental motion command is converted into command positions for the machine drives. In order to generate a defined relative motion between tool and workpiece, command variables must be generated and coordinated for the machine axes involved. In this context, we refer to axes with a channel relationship. The number of axes controlled in a channel and the type of axes – translatory or rotary – are dependent on the machine concept.

For example, in the case of five-axis milling, three translatory and two rotary axes are controlled in one channel. Today, some machines offer the function of controlled their axes in several channels; an automatic multi-slide lathe is a typical example of this. The specific path motions on these machines are specified in the program for the individual channels and the corresponding command variables are generated independently of each other. However, it is possible to incorporate synchronisation points in each of NC programs to coordinate the channels.

Controls allow these machine concepts so that the generation of command variables is organised in separate channels. Accordingly, a separate NC program is started on each channel. Cross-channel synchronisation is executed either using NC commands or via the PLC.