Rockwell Automation Allen-Bradley Micro820

Rockwell Automation Publication 2080-UM002M-EN-E - April 2022 139
Chapter 8
Motion Control
Generally two types of motion control are used in Micro800 controller motion
applications that have Kinetix® 3 servo drives.
• Indexed Motion – Micro800 controller issues position indexes to the
servo drive using Modbus RTU communications or discrete I/O. Used for
simple positioning. See publication CC-QS025
for building block
example.
• PTO Motion – Micro800 controller uses pulse and direction outputs to
the servo drive for precise control of position and velocity with Modbus
RTU communications or discrete I/O for feedback. Micro800 motion
configuration and instructions make programming easy. See publication
CC-QS033
for building block example.
PTO Motion Control Certain Micro830, Micro850, and Micro870 controllers, shown in Table 13,
support motion control through high-speed pulse-train outputs (PTO). PTO
functionality refers to the ability of a controller to accurately generate a
specific number of pulses at a specified frequency. These pulses are sent to a
motion device, such as a servo drive, which in turn controls the number of
rotations (position) of a servo motor. Each PTO is exactly mapped to one axis,
to allow for control of simple positioning in stepper motors and servo drives
with pulse/direction input.
As the duty cycle of the PTO can be changed dynamically, the PTO can also be
used as a pulse width modulation (PWM) output.
PTO/PWM and motion axes support on the Micro830, Micro850, and Micro870
controllers are summarized below.
Table 13 - PTO/PWM and Motion Axis Support on Micro830, Micro850,
and Micro870
Controller PTO (built-in) Number of Axes Supported
10/16 Points
(1)
2080-LC30-10QVB
2080-LC30-16QVB
11
24 Points
2080-LC30-24QVB
(1)
2080-LC30-24QBB
(1)
2080-LC50-24QVB
2080-L50E-24QVB
2080-LC50-24QBB
2080-L50E-24QBB
2080-LC70-24QBB
2080-L70E-24QBB
2080-LC70-24QBBK
2080-L70E-24QBBK
2080-L70E-24QBBN
22