Zero Mark Selection - Siemens SINUMERIK 840D Function Manual

R1: Referencing
10.5 Referencing with incremental measurement systems
10.5.2

Zero mark selection

Function
Referencing of incremental measuring systems is based on the unique position of the encoder
zero mark relative to the overall traversing range of the machine axis. If because of machine-
specific conditions, several encoder zero marks are detected in the traversing range of the
machine axis (for examples, see figure below), a proximity switch must be mounted on the
machine for clear determination of the reference point. The position of the reference point is
then derived from the combination of contact-less proximity switch signal and encoder zero
mark.
BER
O
Figure 10-1
Parameterization
NC: Referencing mode
"Referencing of incremental, rotary or linear measuring systems: Zero pulse on the encoder
track" should be parameterized as referencing mode:
MD34200 $MA_ENC_REFP_MODE[<axis>] = 1
Drive: Zero mark selection
The digital input on the NCU interface to which the proximity switch is connected must be set
in parameter p0493.
Note
Zero mark selection
The processing of the contact-less proximity switch signal is performed exclusively in the drive.
Connection and parameterization, see Section "Hardware signals (Page 296)".
298
Contact-less proximity switch
Measuring gear between the motor and encoder or reduction gear between the motor and
spindle
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA