Glossary
©NationalInstruments Corporation G-7 7344/7334Hardware User Manual
modulo position treatthe position as within the range of total quadrature counts per
revolutionfor an axis
N
noise an undesirable electrical signal—noise comes from external sources such
asthe AC power line, motors, generators, transformers, fluorescent lights,
solderingirons, CRT displays, computers, electrical storms, welders, radio
transmitters, and internal sources such as semiconductors, resistors, and
capacitors.N oise corrupts signals you are trying to send or receive.
noninverting the polarity of a switch (limit switch, home switch, etc.) in active state. If
theseswitches a re active-high,they are said to have non-inverting polarity.
O
open-loop refers to a motion control system where no external sensors (feedback
devices)are used to provide position or velocity correction signals
P
PCI Peripheral Component Interconnect—a high-performance expansion bus
architecture originallydeveloped by Intel to replace ISA and EISA. It is
achievingwidespread acceptance as a standard for PCs and workstations;
it offersa theoretical maximum transfer rate of 1 32 MB/s.
PID proportional-integral-derivativecontrol loop
PIVff proportional-integral-velocity feed forward
port (1)a communications connection on a computer or a remote controller
(2) a digital port, consisting eight lines of digital input and/or output
position breakpoint position breakpoint for an encoder can be set in absolute or relative
quadrature counts.When the encoder reaches a position breakpoint, the
associated breakpoint output immediately transitions.
powercycling turning the host computer offand then back on ,wh ich causesa reset of
the motion control board