User guide

192 6000 Series Programmer's Guide
Ratio Following – Introduction
As part of its standard features, the 6000 Series Controller family allows you to solve
applications requiring Ratio Following.
Compiled
Profiles
You can pre-compile
Following profiles
(saves processing
time). See page 166
for details.
Ratio Following is, essentially, controlled motion based on the measurement of external
motion. This includes concepts such as an electronic gearbox, trackball, slave feed-to-length,
as well as complex changes of ratio as a function of master position. Ratio Following can
include continuous, preset, and registration-like moves in which the velocity is replaced with a
ratio.
The slave may follow in either direction and change ratio while moving, with phase shifts
allowed during motion at otherwise constant ratio. Ratio changes or new moves may be
dependent on master position or based on receipt of a trigger input. Also, a slave axis may
perform Following moves or normal time-based moves in the same application because
Following can be enabled and disabled at will. Product cycles (operations which repeat with
periodic master travel) can be easily specified with the master cycle concept (see page 207).
In Ratio Following, acceleration ramps between ratios will take place over a user-specified
master distance. Product cycles can be easily specified with the master cycle concept.
This chapter highlights the capabilities of the 6000 Following features and provides application
examples. If you need more details on the operation or syntax of a particular command, please
refer to the 6000 Series Software Reference.
Before delving into the specifics of Ratio Following, read on to gain a basic understanding of
how the 6000 controller follows.
What can be a master?
Any axis on the 6000 controller can be slaved to any transducer device input or commanded
position of any other axis. This source is known as the master input, or master. Up to 4
axes (depending on which 6000 product you have) can be following at the same time with the
same or different master.
The options available for master input sources differ by product (see table).
Master Input Options (✓ = yes)
AT6400 AT6200
AT6250 AT6450
610n
615n 620n 625n 6270
OEM- AT6n00
Commanded Position ✓✓✓✓n/a n/a ✓✓✓✓
Input Devices:
• Incremental Encoder ✓✓✓✓✓✓✓✓✓n/a
• ANI Analog Input (-ANI option only) n/a n/a ✓✓n/a ✓ n/a ✓✓n/a
• Linear Displacement Transducer (LDT) n/a n/a n/a n/a n/a n/a n/a n/a ✓ n/a
SERVOS: For servo controllers, an axis may not be slaved to its own feedback device input.
STEPPERS: For stepper controllers, an axis may be slaved to its own encoder input, as long as
that axis does not need encoder feedback for encoder positioning (ENC1 mode) or
stall detection (EPM1 mode).
For more information on assigning a master for a particular slave, refer to Define the Master
and Slave Axes (page 194), or refer to the FOLMAS command description in the 6000 Series
Software Reference.