书上说：
A channel constitutes an "NC" in which one part program can be executed at a time.
Machine axes, geometry axes and positioning axes are assigned to the channels according
to the machine configuration and the current program status (AXIS CHANGE, GEO AXIS
CHANGE, SETMS).
The system assigns each channel its own path interpolator with associated programming.
Each channel can run its own machining program, which is controlled from the PLC.
The following channelspecific functions make it possible for the channels to process part
programs independently:
• Each channel has its own NC Start, NC Stop, RESET.
• One feedrate override and one rapid traverse override per channel.
• Dedicated interpreter for each channel.
• Dedicated path interpolator for each channel, which calculates the path points such that
all the machining axes of the channel are controlled simultaneously from path axes.
• Selection and deselection of tool cutting edges and their length and radius
compensations for a tool in a specific channel.
• Channelspecific frames and frames active in the channel for transforming closed
calculation rules into Cartesian coordinate systems. Offsets, rotations, scalings, and
mirrorings for geometry axes and special axes are programmed in a frame.
For further information about frames:
Reference:
/FB1/Function Manual Basic Functions; Axes, Coordinate Systems, Frames (K2), Sec.:
"External work offset"
• Display of channelspecific alarm responses.
• Display of current machining sequence (axis position, current G functions, current
auxiliary functions, current program block) for each channel.
• Separate program control functions for each channel.
These functions (with the exception of the display functions) are controlled and checked by
the PLC with interface signals.
Channels in the same mode group always have to be operated in the same mode
(AUTOMATIC, JOG, MDA).