Siemens SINUMERIK 840D Function Manual page 297

Reference cam
● Connection
The reference cam signal can be connected to a digital input of an external PLC I/O module
or to a fast input on the NCU X142 interface.
● NC/PLC interface signal
The reference cam signal must be transferred from the PLC user program to the axial NC/
PLC interface:
DB31, ... DBX12.7 (deceleration of reference point approach)
Zero mark selection
If during the reference point approach of the axis or spindle several zero marks of the
measuring system are detected (e.g. measuring gear between the motor and encoder), then
the specific zero mark must be selected with an additional proximity switch signal.
● Connection
The proximity switch must be connected to a fast digital input on the NCU X122 or X132
interface.
● Activation
In order that the proximity switch signal is evaluated, the digital input to which the proximity
switch is connected must be selected in drive parameter p0493 for the axis/spindle.
Equivalent zero mark
If the used measuring system does not provide a zero mark signal, an equivalent zero mark can
be created via a proximity switch signal.
● Connection
The proximity switch must be connected to a fast digital input on the NCU X122 or X132
interface.
● Activation
In order that the proximity switch signal is evaluated, the digital input to which the proximity
switch is connected must be selected in the p0494 or p0495 drive parameter for the axis/
spindle.
Overview
Signal
Reference cam
Zero mark selection
External zero mark or equivalent
zero mark
Additional information
● NCU interfaces: Equipment Manual
Connect > Digital inputs/outputs
● Drive parameter: SINAMICS S120/S150 List Manual
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
10.5 Referencing with incremental measurement systems
Connection: Digital input via
Ext. PLC I/O module or NCU:
X142
NCU: X122 or X132
NCU: X122 or X132
R1: Referencing
Set
PLC user program:
DB31, ... DBX12.7
Drive parameter: p0493
Drive parameter: p0494 or p0495
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