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User Manual
Chapter 8
GFK-1742F
Jan 2020
Follower Motion
223
Chapter 8:
Follower Motion
Configuring the DSM314 for Follower Control Loop = Enabled (in the configuration software
Axis Configuration tab) allows each Servo Axis (slave) to respond to a Master Axis input using
a programmable slave: master ratio. The DSM314 defines the slave: master ratio as the ratio
of two integer numbers A and B. The basic formula for computing Follower motion is:
Follower Servo Axis motion (slave axis) = Master Axis motion x (A/B)
or
slave : master ratio = A : B ratio
If a Jog, Move at Velocity or Execute Motion Program command is also initiated, the axis
motion will represent the combination of the Master Axis motion and the internally
commanded motion. This Chapter provides details of servo motion related to the Master
Axis input. Refer to Chapter 9 for additional information about combined Follower and
commanded motion.
When the Enable Follower %Q bit is turned ON, an axis will immediately begin following the
selected Master Source unless a Follower Enable Trigger input has been selected. If a
Follower Enable Trigger input has been selected, then the Enable Follower %Q bit must be
ON and an OFF to ON transition of the trigger input must occur. The external trigger input
CTL01 - CTL032 is selected in the configuration software.
The DSM314 always operates the follower
axis in “ramp makeup” mode. If the master axis
has a nonzero velocity when the follower is enabled, the slave axis will accelerate at the
configured Ramp Makeup Acceleration to a speed that allows it to catch up to the master
axis.
8.1
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