Siemens SINUMERIK 840D sl Programming Manual page 486

Work preparation
3.1 Flexible NC programming
Boundary conditions
Non-synchronous start of execution of following blocks after WAIT markers
In the case of channel coordination using WAIT markers, execution of the following blocks may
start non-synchronously. This behavior occurs if an action is triggered in one of the channels to
be synchronized immediately before reaching the common WAIT marker; the consequence of
which is implicit repositioning (REPOSA) in this delete distance-to-go.
Assumption: Current axis assignment in channels 1 and 2
● Channel 1: Axes X1 and U
● Channel 2: Axis X2
Table 3-2
N100
WAITM(20,1,2)
Start of the GETD(U)
processing:
●
●
●
End
N110 G0 X1=100
486
Time sequence in channels 1 and 2
Channel 1
...
N200 GETD(U)
Axis interchange
N210
Delete distance-to-
WAITM(20,1,2)
go
N220 G0 X2=100
REPOSA
Channel 2 Description
Arbitrary processing in channels 1 and 2
...
Channel 1: reaches the WAIT marker and waits for
synchronization with channel 2
Channel 2: Requests axis U from channel 1
Channel 1: Processing of GET(U) in the background
Channel 2: reaches the WAIT marker. ⇒ This com‐
pletes the synchronization of channels 1 and 2
Channel 2: Start of processing of N220
Channel 1: Staggered start of processing of N110
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
NC programming