Siemens SIMATIC FM 453 Manual page 217

9.2.3 Reference Point Approach
Overview
In Reference-point approach mode, the direction keys (R+ or R–) or Start are
used to position the axis to a point (reference-point coordinate MD16) speci-
fied in the machine data.
The axis is thus synchronized (see Section 9.6.4).
The overrideis set to 100% for the reducing speed.
An active zero offset or Set actual value is reset.
Machine Data The following table lists the machine data that is of significance for refer-
ence-point approach:
16
18
27
28
29
34
MSR stands for measurement system raster (see Section 5.3.1)
Handling by
When an absolute encoder is used, only the reference point coordinate de-
the User fined as a fixed point on the axis is approached in Reference-point approach
mode.
When an incremental encoder is used, the user has two options for recording
the reference point:
FM 453 Servo Drive / Step Drive Positioning Module
C79000-G7076-C453-01
MD Designation
Reference- –1,000,000,000 – +1,000,000,000
point coordi-
nate
Type of refer- 0 = direction +, zero ref. mark right
ence-point ap- 1 = direction +, zero ref. mark left
proach 2 = direction –, zero ref. mark right
3 = direction –, zero ref. mark left
(reference-
4 = direction +, RPS center
point ap-
5 = direction –, RPS center
proach direc-
8 = direction +, RPS edge
tion)
9 = direction –, RPS edge
Reference- –1,000,000,000 – +1,000,000,000
point shift
Referencing 10...500 000 000
speed see Section 5.3.1, Dependencies
Reducing 10...500 000 000
speed see Section 5.3.1, Dependencies
dig. Inputs 5 = reference point switch for
reference point approach
6 = reversing switch for reference point ap-
proach
with connected reference-point switch (RPS)
without connected reference-point switch (RPS).
Description of Functions
Value/Meaning Comments/
Unit
(MSR)
Zero refer-
ence mark:
See zero ref-
erence mark
selection,
Figure 5-5
(MSR)
(MSR/min)
(MSR/min)
Assigned de-
pending
on input
9-17