User manual

Chapter 1 Introduction to the 2762-17
ADVANCED MICRO CONTROLS INC.
11
Positioning Setup Parameters (continued)
Overshoot Offset
The 2762-17 uses the Overshoot Offset to
determine how far away from the Target Position
to drive the load before beginning the approach to
the Target Position. If the starting position is
between the Target Position and Overshoot
Offset, or on the opposite side of the Target
Position, the 2762-17 will drive the load to the
Overshoot Offset before beginning the approach.
The Overshoot Offset is also used when backing
off from the Target Position if the previous
attempt to reach it failed.
The Overshoot Offset can be programmed to
any value between (Low Speed Offset +1) and
Full Scale Count.
If a positive approach is defined and (Target
Position + Overshoot Offset) is greater than the
Upper Travel Limit, the module will issue an 'Invalid Profile' error message when a move
profile is initiated. The same error message will be issued if a negative approach is defined and
(Target Position - Overshoot Offset) is less than the Lower Travel Limit.
Low Speed Offset
The Low Speed Offset defines the
position that the motor switches from high
to low speed. It is used in two ways.
!
When approaching the Target
Position from the correct direction,
(Target Position ± Low Speed
Offset) is the point at which the
motor switches from high to low
speed.
!
When traveling towards the Over-
shoot, the motor will switch to low
speed when the position is
(Overshoot ± Low Speed Offset). It
will then travel at low speed to the
Overshoot position, turn off the
motor, and reverse direction before
completing the profile.
The Low Speed Offset can be programmed to zero or from (Stop Offset + 1) to (Overshoot
Offset - 1). Setting the Low Speed Offset to zero disables the high speed motor output. All
movement will be at low speed if the Low Speed Offset equals zero.
1.599 in
Overshoot Offset
Target
Overshoot
Negative Approach
1.599 in
Overshoot Offset
Overshoot
Target
Positive Approach
Figure 1.6 Overshoot Offset
.997 in
Target
Overshoot
Negative Approach
Low Speed
Offset
Overshoot
Target
Positive Approach
Low Speed
.997 in
Low Speed
Offset
.997 in
Low Speed
Offset
Low Speed
.997 in
Low Speed
Offset
Overshoot -
Low Speed
Overshoot -
Low Speed
Figure 1.7 Low Speed Offset