Glossary
AT-MIO-16X User Manual G-18
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National Instruments Corporation
PCMCIA an expansion bus architecture that ha s found widespread acceptance as
a de facto standard in notebook-si z e co mpu t er s. It o rigi na ted a s a
specification for add-on memory cards written by the Personal
Computer Memory Card International Association.
peak to peak a measure of signal amplitude; the difference between the highest and
lowest excursions of the signal
PFI programmable function input
PGIA programmable gain instrumentation amplifier
photoelectric sensor an electrical device that responds to a change in the inten sity of the light
falling upon it
PID control a three-term control mechanism combining proportional, integral, and
derivative control actions. Also see proportional control, integral
control, and derivative control.
pipeline a high-performance processor structure in which the completion of an
instruction is broken into its elements so that several elements can be
processed simultaneously from different instructions
PLC programmable logic c on troller —a high ly relia ble spe cial -p urpose
computer used in industrial monitoring and control applications. PLCs
typically have proprietary programming and networking protocols, and
special-purpose digital and analog I/O ports.
Plug and Play devices devices that do not require dip switches or jumpers to configure
resources on the devices—also called switchless devices
Plug and Play ISA a specification prepared by Microsoft, Intel, and other PC-related
companies that will result in PCs with plug-in boards that can be fully
configured in software, without jumpers or switches on the boards
port (1) a communications connection on a compute r or a remote controller
(2) a digital port, consisting of four or eight lines of digital input and/or
output
posttriggering the technique used on a DAQ board to acquire a programmed number
of samples after trigger conditions are met
potentiometer an electrical device the resistance of which can be manually adjusted;
used for manual adjustment of electric al circuits and as a transducer for
linear or rotary position