AMCI SV160E2, User Manual, Page: 29 / 120

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SV160E2 User Manual
M
OTION
C
ONTROL
29
Basic Move Types
Relative Move
Relative Moves move an offset number of steps (n)
from the current Profile Position (A). A trapezoidal
profile is shown to the right, but Relative Moves can
also generate triangular profiles. The command’s Tar-
get Position is the move’s offset. The offset can be in
the range of -1,073,741,824 to +1,073,741,823
counts. Positive offsets will result in clockwise moves,
while negative offsets result in counter-clockwise
moves.
Relative Moves allow you to move your machine without having to calculate absolute posi-
tions. If you are indexing a rotary table, you can preform a relative move of 30° multiple times
without recalculating new target positions in your controller. If you perform the same action
with Absolute Moves, you would have to calculate your 30° position followed by your 60°
position, followed by your 90° position, etc.
Relative Moves can be brought to a Controlled Stop by using the Hold Move Command from your host con-
troller. When the command is accepted, the axis will immediately decelerate at the programmed rate and stop.
When stopped successfully, the SV160E2 will set a
In_Hold_State bit in the input data table. The Relative
Move can be restarted with the Resume Move command from the host controller or the move can be aborted
by starting another move. The Resume Move command allows you to change the move’s Programmed Speed,
Acceleration Value, and Deceleration Value. The Target Position cannot be changed with the Resume Move
Command.
Controlled Stops

The move completes without error.

You issue a Hold Move command through the Network Output Data. Note that your holding position
will most likely not be the final position you commanded. You can resume a held Relative Move by
using the Resume Move command or the move can be aborted by starting another move. The use of the
Hold Move and Resume Move commands is further explained in the
Controlling Moves In Progress
section starting on page 36.
Immediate Stops

You issue an Immediate Stop command through the Network Output Data.

An inactive-to-active transition on an input configured as an E-Stop Input. A Reset Errors command
must be issued before moves are allowed again.

A CW or CWW Limit Switch is reached. A Reset Errors command must be issued before moves are
allowed again.

If set to a non-zero value, the Immediate Stop Deceleration parameter, described on page 26, is used to
decelerate the load.
Figure R2.3 Relative Move
SP
E
E
D
POSITION
A
A+n