Kollmorgen AKD PDMM series, User Manual

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AKD PDMM User Guide | Glossary
Term Description
Precedence
In arithmetic and algebra, when a number or expression is both preceded and
followed by a binary operation, a rule is required for which operation should be
performed first. From the earliest use of mathematical notation, multiplication
took precedence over addition, whichever side of a number it appeared on.
Thus 3 + 4 × 5 = 5 × 4 + 3 = 23.
To change the order of operations, we use parentheses (). Thus, if we want to
force addition to precede multiplication, we write
(3 + 4) × 5 = 35.
Primary
Encoder Describes the feedback mounted onto the motor the drive is controlling. The
Primary Encoder is used to force commutation. See also Encoder.
Probe See Softscope - Probe item
PROFIBUS
PROFIBUS (Process Fieldbus) is a standard for fieldbus communication in
automation technology. PROFIBUS is the only fieldbus that can be used in
equal measure in production automation and process automation and has since
become a global market leader. Worldwide
There are two variations of PROFIBUS; the most commonly used DP, and the
lesser used PA variations:
l
PROFIBUS DP (Decentralized Peripherals) is used to operate sensors and
actuators via a centralized controller in production technology. The many stand-
ard diagnostic options, in particular, are focused on here. Other areas of use
include the connection of "distributed intelligence", i.e. the networking of mul-
tiple controllers to one another (similar to PROFIBUS FMS).
Data rates up to
12 Mbit/s on twisted pair cables and/or fiber optics are possible.
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PROFIBUS PA (Process Automation) is used to monitor measuring equipment
via a process control system in process engineering. This PROFIBUS variant
is ideal for explosion-hazardous areas (
Ex-zone 0 and 1). Here, a weak current
flows through bus lines in an intrinsically safe circuit so that explosive sparks
are not created, even if a malfunction occurs. The disadvantage of this variant
is the slower data transmission rate of 31.25 kbit/s.
Programming The act of performing a sequence of instructions or commands.
Quasi-closed
loop posi-
tioning A technique using a stepping motor and encoder in which open loop moves are
completed, after which an encoder/counter is checked and, if necessary, a
small final move or moves is used to achieve the desired accuracy.
Radial Run-
out The radial runout is the positioning error of a rotary table’s centering diameter in
the horizontal direction when the table is rotating in the horizontal plane.
Ramping
The gradual acceleration and deceleration of a stepping motor, essential if per-
formance beyond the start/stop range is required. The slope of the ramp is a
function of screw pitch, load, drive voltage and design, and motor.
Real-time
computing
RTC is the study of hardware and software systems which are subject to a
"real-time constraint" (i.e. operational deadlines from event to system
response). By contrast, a non-real-time system is one for which there is no
deadline, even if fast response or high performance is desired or even pre-
ferred. The needs of real-time software are often addressed in the context of
real-time operating systems, and synchronous programming languages, which
provide frameworks on which to build real-time application software.
A real time system may be one where its application can be considered (within
context) to be mission critical.
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