Signals To Channel (Db21; Signals From Channel (Db21 - Siemens SINUMERIK 840D sl Function Manual

19.1.6

Signals to channel (DB21, ...)

DB21, ...
DBX6.2 Delete distance-to-go (channel-specific)
Edge evaluation: No
Signal state 1 or edge Delete distance-to-go (channel-specific):
change 0 → 1
IS "Delete distance-to-go (channel-specific)" for path axes is only active in AUTOMATIC mode.
The rising edge of the interface signal is only effective for the axes involved in the geometry grouping.
These are also stopped with a ramp stop and their distance-to-go deleted (setpoint - actual value
difference). Any remaining following error is still corrected. The next program block is then started.
IS "Delete distance-to-go (channel-specific)" is therefore ignored by positioning axes.
Remark:
IS "Delete distance-to-go" does not influence the running dwell time in a program block with dwell
time.
Signal state 0 or edge No effect
change 1 → 0
Signal irrelevant for ... Positioning axes
Application exam‐ To terminate motion because of an external signal (e.g. measuring probe)
ple(s)
Special cases, Delete distance-to-go (channel-specific)
errors, ....
When the axes have been stopped with IS "Delete distance-to-go" the next program block is prepared
with the new positions. After a "Delete distance-to-go", geometry axes thus follow a different contour
to the one originally defined in the part program.
If G90 is programmed in the block after "Delete distance-to-go" it is at least possible to approach the
programmed absolute position. On the other hand, with G91, the position originally defined in the
part program is no longer reached in the following block.
Corresponding to ... DB31, ... DBX2.2 (delete distance-to-go (axis-specific))
19.1.7

Signals from channel (DB21, ...)

DB21, ...
DBX36.6 Channel-specific NCK alarm is active
Edge evaluation: No
Signal state 1 or edge At least one NCK alarm is present for this channel.
change 0 → 1
Thus the following group interface signal is also set:
DB10 DBX109.0 (NCK alarm is present)
The PLC user program can interrogate whether processing for the channel in question has been
interrupted because of an NCK channel:
DB21, ... DBX36.7 (NCK alarm with processing stop present).
Signal state 0 or edge No NCK alarm is active for this channel.
change 1 → 0
Corresponding to ... DB21, ... DBX36.7 (NCK alarm with processing stop pending)
DB10 DBX109.0 (NCK alarm pending)
Additional references Diagnostics guide
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Signal(s) updated: Cyclically
Signal(s) updated: Cyclically
Z1: NC/PLC interface signals
19.1 Various interface signals and functions (A2)
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