Positioning Velocity Curve; Velocity Curve On Approaching A Target Position (Basic Shape) - Siemens SIMATIC FM 351 Installation Manual

Principles of Positioning
2.2
Introduction
2
Velocity Curve on
Approaching a
Target Position
Target Approach
Evaluation by
Program
2-4

Positioning Velocity Curve

This chapter gives an overview of the basic curve for positioning on a target.
The velocity and also the basic curve mainly depend on the possibilities pro-
vided by the power controller which you are using.
We show you the basic sequence on approaching a target position in Fig. 2-3
below.
For the sake of simplicity we have assumed that the velocity changes linearly
over the distance traveled.
The following basic curve for positioning is then produced:
–1000 mm
v
creep
Switchover difference, positive
1
Switch-off difference, positive
2
Figure 2-3 Velocity Curve on Approaching a Target Position (Basic Shape)
Please refer to Chapter 2.3 for the target approach.
The effect of the FM 351 monitoring is shown. In addition, you can see when
the FM 351 signals reaching a position.
You can determine all the statuses during positioning from the response sig-
nals. Please read Chapter 12 for more information.
0
1
v
rapid
Standstill range
3
Target range
4
Target
1000 mm
4
3
2
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02