National Instruments NI-Motion - Manual (Page 294)

Glossary
NI-Motion User Manual G-6 ni.com
P
PCI peripheral component interconnect—a high-performance expansion bus
architecture originally developed by Intel to replace ISA and EISA. PCI 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) Communications connection on a computer or a remote controller;
(2) Digital port, consisting of eight lines of digital input and/or output.
position breakpoint Allows a motor to stop at a given point so that another action, such as a data
acquisition or an image acquisition, can take place. You can set position
breakpoints in absolute or relative quadrature counts. When the encoder
reaches a position breakpoint, the associated breakpoint output
immediately transitions.
PWM pulse width modulation—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 multiplied by four.
R
RAM random-access memory
relative breakpoint Sets the position breakpoint for an encoder in relative quadrature counts.
relative position Destination or target position for motion specified with respect to the
current location, regardless of its value.
relative position mode Position relative to current position.