Reference Point Approach With Absolute Encoders; Reference Point Approach In Rotary Absolute Encoders With External Zero Mark - Siemens SINUMERIK 828D Function Manual

R1: Reference point approach
15.9 Referencing with absolute value encoders
Creep velocity
If with the approach of BERO, it is to be proceeded with the parameterized reference point creep velocity
(MD34040 $MA_REFP_VELO_SEARCH_MARKER) then "BERO with projected start velocity with spindles" must
be parameterized as reference mode:
MD34200 $MA_ENC_REFP_MODE = 7
15.9.6

Reference point approach with absolute encoders

Traversing movement release
If for a mchine axis with adjusted absolute value encoder as active measuring system, reference point traversing
is activated (manual in the mode JOG-REF or automatic according to part program instruction G74), the machine
axis travels depending on the parameterized release traversing movement.
MD34330 $MA_REFP_STOP_AT_ABS_MARKER = <Value>
Value Meaning
0 Traversing is enabled.
When reference point approach is initiated, the machine axis moves to the reference point
position. Reference point approach is completed when the reference point position is
reached.
1 Traversing is not enabled.
After the activation of the reference point travel, the machine axis does not travel and the
reference point travel is immediately completed.
15.9.7

Reference point approach in rotary absolute encoders with external zero mark

Function
To be able to use the reference point approach with a zero mark, as is usual in incremental encoders (refer to
Chapter "Referencing in incremental measuring systems") even with absolute encoders, the missing HW zero
marks are created in software form once every encoder revolution, always at the same position within the
rotation.
Difference compared to referencing with incremental encoders
An absolute encoder with replacement zero mark should not be considerd as a complete equivalent of an
incremental encoder. All the properties of the absolute encoder are retained. The following table lists the different
properties of incremental and absolute encoders:
Table 15-1 Properties of incremental and absolute encoders
Feature
Encoder type
1242
Incremental encoder
= 1
Absolute encoders
MD30240 $MA_ENC_TYPE
= 4
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
Basic Functions