Siemens SINUMERIK 840D sl Function Manual page 357

Figure 6-4
Example: WAITMC and read-in disable
M555 is output in channel 3 while the axis is traversing and generates a read-in disabled (RID).
Because the WAITMC is added to block N312, the wait marker is set and channel 2 continues
to travel. The read-in disable causes the program processing in channel 3 to stop.
Note
For active G64, a WAITMC(...) block does not create its own block but is added to the previous
block. A drop in velocity must be prevented when continuous-path mode is active. A WAITMC
is therefore fulfilled if the preceding block is halted, e.g. by a read-in disable.
Channel 2:
Program code
N112 G18 G64 X200 Z200 F567
Extended Functions
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
Conditional wait in path controlled operation with three involved channels (schematic)
Comment
; Machining in channel 2.
K5: Channel synchronization, axis interchange
6.1 Channel synchronization
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