Kollmorgen AKD PDMM series, User Manual

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AKD PDMM User Guide | Glossary
Term Description
Online/Offline Active or connected/inactive or disconnected.
Open loop
positioning
A positioning technique, typically utilizing stepping motors, in which the con-
troller issues a sequence of commands to the motor without any absolute
means of detecting if the move has in fact been made. When the load and
move velocity and acceleration are appropriately defined, open loop positioning
is capable of extended operation without losing steps.
OpenGL
OpenGL (Open Graphics Library) is a standard specification defining a cross-
language cross-platform API for writing applications that produce 2D and 3D
computer graphics.
The Softscope uses this API to implement graphical manipulations.
Optical
encoder
A linear or angular position feedback device, typically providing incremental
two channel information in quadrature format (sine or square waves with a 90
degree phase shift between each channel). Such two channel information
allows simple counter circuits to function as absolute position indicators.
Orthogonality
The degree of perpendicularity, or squareness, between the two axes in an X-Y
or X-Z table. This parameter is usually measured in arc-seconds or micro radi-
ans.
P-code
a P-code machine or pseudo-code machine is a specification of a CPU (Cen-
tral Processing Unit) whose instructions are expected to be executed in soft-
ware rather than in hardware.
Programs that have been translated to p-code are executed (interpreted) by a
software program that emulates the behavior of the CPU specification.
Periodicity
Motor systems having a reciprocating or oscillating motor that operates syn-
chronously with the periodicity of the source which supplies the electrical
energy.
The period of execution of a pipe is the time spent between two successive
computations of set values for the same pipe. The period of execution of a pipe
is specified by the PERIOD parameter of the input pipe block.
Phase current
The rated current which a stepping motor requires to generate its rated holding
torque. This value is usually based on unipolar (half-coil) operation. This choice
of how the motor is wired has significant impact on performance.
Phase
sequence The specific sequence of coil current changes used to advance a stepping
motor clockwise and counter-clockwise, in either full or half step modes.
Pitch
For lead-screws specified in British units, the number of full rotations required
to advance the nut 1î. For example, a 5 pitch lead-screw has a lead of 0.200î.
Metric screws are specified by lead only, in millimeters.
The pitch is a rotation (angular deviation from the ideal straight line of travel)
around an axis in the horizontal plane perpendicular to the direction of travel.
For the X-axis travel, a pitch will cause an Abbé error in the X and Z directions
An angular deviation possible in positioning systems, in which the table’s lead-
ing edge rises or falls as the table translates along its direction of travel. This
represents rotation around a horizontal axis, perpendicular to the direction of
travel.
PLCopen
A vendor -and product- independent worldwide association active in Industrial
Control and aiming at standardizing PLC file formats based on XML
Position
counts AKD PDMMscales this so that the low 32 bits are the position per revolution
(mechanical or electrical?).
Pragma A compiler directive communicating additional "pragmatic" information.
503 Kollmorgen™ | December 2012