Siemens SINUMERIK 840D sl Function Manual page 2127

DB21, ...
DBB4 Feed rate override
Signal state 1 or The feed rate override can be defined via the PLC in binary or Gray coding.
edge change
With binary coding, the feed value is interpreted in %.
0 → 1
0% to 200% feed changes are possible, in accordance with the binary value in the byte.
The following permanent assignment applies:
Binary values > 200 are limited to 200%.
The machine data:
MD12100 $MN_OVR_FACTOR_LIMIT_BIN (limit for binary-coded override switch)
can be used to additionally limit the maximum feed rate override.
With Gray coding, the individual switch settings are assigned to the following codes:
Basic logic functions: NC/PLC interface signals (Z1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Detailed Description
2.16 Feeds (V1)
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