National Instruments 7340 PCI Benutzerhandbuch

© National Instruments Corporation

open-loop

refers to a motion control system where no external sensors (feedback 
devices) are used to provide position or velocity correction signals

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

quadrature counts

encoder line resolution times four

RAM

random-access memory

relative breakpoint

sets the position breakpoint for an encoder in relative quadrature counts