Siemens SINUMERIK 828D Function Manual page 1233

Positive edge evaluation
In the case of a referencing operation with a positive edge evaluation of the BERO signal:
MD34120 $MA_REFP_BERO_LOW_ACTIVE = TRUE
synchronization is with the next encoder zero mark encountered after the BERO is approached.
Mechanically, the BERO must be sized in such a way that the positive BERO signal covers the entire width of the
encoder zero mark.
Enable
The "Referencing in follow-up mode" function is enabled with:
MD34104 $MA_REFP_PERMITTED_IN_FOLLOWUP = TRUE
Starting the referencing operation
If the machine axis is operating in the follow-up mode at the start of reference point traversing, (DB31,... DBX61.3
== TRUE) the measuring system will be referenced in the follow-up mode.
If the machine axis is not operating in the follow-up mode at the start of reference point traversing, the "normal"
from the NC controlled reference point travels is carried out.
Referencing in follow-up mode can be started in the following modes:
• JOG-REF: Traversing keys
• AUTOMATIC: Part program command G74
Sequence of referencing operation (JOG-REF mode)
1. Activate follow-up mode of machine axis:
DB31, ... DBX1.4 (follow-up mode) = 0
DB31, ... DBX2.1 (servo enable) = 0
2. Take into account activation of follow-up mode:
DB31, ... DBX61.3 (follow-up mode active) = 1
3. Switch to JOG-REF mode.
4. External movement of machine axis across encoder zero mark or parameterized number of distance-coded
reference marks. The referencing operation is started internally in the NC as soon as the machine axis is
moved:
DB31, ... DBX61.4 (axis/spindle stationary) = 0
5. The measuring system is referenced after the encoder zero mark or the assigned number of distance-coded
reference marks have been successfully detected:
DB31, ... DBX60.4/60.5 (referenced/synchronized 1 / 2) = 1
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
R1: Reference point approach
15.8 Referencing in follow­up mode
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