Kollmorgen AKD PDMM series, User Manual

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AKD PDMM User Guide | Glossary
Term Description
Reference
Counting
In computer science, reference counting is a technique of storing the number of
references, pointers, or handles to a resource such as an object or block of
memory. It is typically used as a means of de-allocating objects which are no
longer referenced.
Reference sit-
uation
Any situation that indicates that the home position has been found.
Reference
switch
An adjustable hardware switch for indicating a home position.
Refresh GUI command that re-loads the data from the drive and redraws the display.
Regen
resistor
Regen Resistors are a necessity on all horizontal motion (bridge/trol-
ley/monorail) applied Variable Speed drives.
Power returns to the drive when the connected motor is driven in generator
mode and is called regenerative power. This power is absorbed by charging the
bus smoothing capacitor with the regen resistor consuming all that regen-
erative power exceeding the chargeable energy of the capacitor.
Relative
encoder
See Incremental encoder.
Repeatability,
bi-directional
The difference in absolute position reached when returning to a given position
from the same direction. This value may mask significant amounts of back-
lash.
Repeatability,
uni-directional
The difference in absolute position reached when returning to a given position
from the opposing direction. This value is usually larger than the unidirectional
repeatability.
Resolution
The resolution is the smallest possible movement that can be achieved by a
system. It can be defined at the electronics, encoder and mechanics level.
The distance a stage can be commanded to move in a single step. For servo
systems, the basic increment produced by its optical encoder, or any other
feedback device.
Resonance,
midrange
A parasitic oscillation which is endemic to stepping motors, although frictional
loads may mask its effect. It typically sets in from 5-15 revolutions per second,
and can easily cause a loss of synchronization (stalling). All NEAT high speed
micro-stepping drives effectively suppress this resonance.
Resonance,
primary
The rotor inertia of a stepping motor, together with its spring-like holding torque,
constitutes a basic spring-mass oscillator. In the absence of sufficient damp-
ing, stepping at certain frequencies may excite resonance in this system, or
resonate with the stage or load, resulting in loss of synchrony. The addition of
system damping, micro-stepping, or ramping through problematic speeds will
usually eliminate this resonance.
Rising Edge
A rising edge is the transition of a digital signal from low to high. It is also
named positive edge.
RJ-45 Internet plug type.
Roll
An angular deviation from an ideal straight line motion, in which the positioning
table rotates around its axis of travel as it translates along that axis.
RS-232c
A popular protocol for transmitting digital data over two lines in a bit-serial for-
mat. RS-232C specifies signal levels, data formats, maximum transmission
distance, etc.
Runtime
In computer science, runtime or run time describes the operation of a computer
program, the duration of its execution, from beginning to termination (compare
compile time).
505 Kollmorgen™ | December 2012