National Instruments 7340 PCI - Manual (Page 62)

Glossary
© National Instruments Corporation G-7 NI 7340 User Manual
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 originally developed by Intel to replace ISA and EISA. It is
achieving widespread acceptance as a standard for PCs and workstations;
it offers a theoretical maximum transfer rate of 132 MB/s.
PID proportional-integral-derivative control loop
PIVff proportional-integral-velocity feed forward
port (1) a communications connection on a computer or a remote controller;
(2) a digital port, which consists of 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.
power cycling turning the host computer off and then back on, which causes a reset of
the motion control board
PWM Pulse Width Modulation—a method of controlling the average current in
a motor phase winding by varying the on-time (duty cycle) of transistor
switches
PXI PCI eXtensions for Instrumentation
Q
quadrature counts encoder line resolution times four
R
RAM random-access memory
relative breakpoint sets the position breakpoint for an encoder in relative quadrature counts