Siemens SINAMICS S120 Function Manual page 258

Extended Functions
Function module "basic positioner"
Reference point approach for incremental measurement systems
When the reference point approach (in the case of an incremental measuring sys-
tem), the drive is moved to its reference point. In so doing, the drive itself controls
and monitors the complete referencing cycle.
Incremental measuring systems require that after the machine has been powered
up, the absolute dimension reference is established to the machine zero point.
When powering-up the position actual value x
x = 0. Using the reference point approach, the drive can be reproducibly moved to
0
its reference point. The geometry with a positive starting direction (p2604 = "0") is
shown in the following.
Reference cam
p2612
Fig. 4-27
Travel to the reference cam is initiated using the signal at binector input p2595
(start referencing) when the reference point approach is simultaneously selected
(0 signal at binector input p2597 (select referencing type)) (p2607 = 1). During the
complete referencing operation, the signal at binector input p2595 (start referenc-
ing) must be set otherwise referencing is interrupted. As a result of the start, status
signal r2684.11 (reference point set) is reset.
4-258
Approach
direction
A
Reference point coordinate
p2598
p2599 r2599
| v |
p2605
p2611
p2608
(0)
Reference zero mark
Start direction
p2604
(0)
Example, reference point approach using reference cams
in the non-referenced state is set to
0
p2600
B
(2599 )
1
3
2
© Siemens AG 2006 All Rights Reserved
SINAMICS S120 Function Manual, 03/2006 Edition
s
p2610
p2609
p2606