Siemens SINUMERIK 840D sl, Function Manual

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Detailed description
2.3 Feedrate control
Basic logic functions: Feeds (V1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
35
Channel-specific "Feedrate override" DB21, ...DBB4 / "Rapid traverse override" DB21, ...DBB5
One enable signal and one byte is provided on the PLC interface for the override factor for
each of the feedrate types.
IS "Feedrate override" (DB21, ... DBB4)
IS "Feedrate override active" (DB21, ... DBX6.7)
IS "Rapid traverse override" (DB21, ... DBB5)
IS "Rapid traverse override active" (DB21, ... DBX6.6)
The interface for the override can be provided by the PLC in binarycoded or Graycoded
format.
Machine data:
MD12020 OVR_FEED_IS_GRAY_CODE (path feedrate override switch Gray-coded)
and
MD12040 OVR_RAPID_IS_GRAY_CODE (rapid traverse override switch Gray-coded)
are used to define whether binary or Gray coding is active.
The following permanent assignment applies to binary coding:
Code Override factor
00000000 0,00 ≙ 0%
00000001 0,01 ≙ 1%
00000010 0,02 ≙ 2%
00000011 0,03 ≙ 3%
00000100 0,04 ≙ 4%
. .
. .
. .
01100100 1,00 ≙ 100%
. .
. .
. .
11001000 2,00 ≙ 200%
With Gray coding, the override factors corresponding to the switch setting are entered in
machine data:
MD12030 OVR_FACTOR_FEEDRATE [n]
(analysis of path feedrate override switch)
or
MD12050 OVR_FACTOR_RAPID_TRA [n] (analysis of rapid traverse override switch).
An active feedrate override acts on all path axes assigned to the current channel.
An active rapid traverse override acts on all axes moving with rapid traverse and assigned to
the current axis.
If no dedicated rapid traverse override switch is used, the system can be switched between
rapid traverse override and feedrate override. In this case, feedrate overrides above 100%
are limited to 100% rapid traverse override.