User`s manual

8-2 Motion Mate™ DSM314 for Series 90™-30 PLCs User's Manual – January 2001 GFK-1742A
8
Master Sources
A DSM314 Servo Axis can be configured to follow any two of eight possible master input sources.
The two sources are identified as Source 1 and Source 2. A
Follower Master Source Select
%Q
bit determines whether Source 1 or Source 2 is the active source. The available selections for
Source 1 and Source 2 are:
•
Axis 1 Commanded Position
•
Axis 1 Actual Position
•
Axis 2 Commanded Position
•
Axis 2 Actual Position
•
Axis 3 Commanded Position
•
Axis 3 Actual Position
•
Axis 4 Commanded Position
•
Axis 4 Actual Position
Note that follower motion is summed with
Jog
,
Move at Velocity,
or Motion Programs. If a slave
axis is following a master input at velocity V1, and a
Jog
is commanded at velocity V2, the axis
will move at velocity V1 + V2.
External Master Inputs
Actual Position
for Axis 1 - Axis 4 represent external master axis sources. An encoder connected
to the axis or the feedback of a servo system may be used as an actual position source. The
DSM314 follower loop allows a slave axis to follow a selected external source as shown in this
example:
Example 1: Following Axis 3 Actual Position Master Input
In this example, a graph of velocity (v) versus time (t) shows the velocities of the master input
(Actual Position 3), and the slave axis that is following the master. The DSM314 is configured
with
Follower Master Source
1 = Actual Position 3
and the
Select Master Source
%Q bit is
OFF. The A:B ratio is 1:1. The velocity profile of the following (slave) axis is identical to the
master input.
Figure 8-1.
Following Encoder 3 Master Input
t
v
t
v
a45327
Master
Follower
A
:B
R
atio
=
1:1