Siemens SINUMERIK 840Di Function Manual page 1450

Detailed Description
2.4 Referencing with incremental measurement systems
2.4.3 Phase 2: Synchronization with the zero mark
Phase 2: Graphic representation
Fig. 2-4 Phase 2: Synchronization with the zero mark
Phase 2: Start
Phase 2 is automatically started when phase 1 has been completed without an alarm.
Initial situation: The machine axis is positioned on the reference cam.
Zero mark search direction
The zero mark is searched for in the parameterized direction and approached:
MD34050 $MA_REFP_SEARCH_MARKER_REVERSE (direction reversal on reference
cam)
2-10
Reference Point Approach (R1)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0