National Instruments NI-FBUS - Manual (Page 144)

Glossary
NI-FBUS Configurator User Manual G-8 ni.com
O
Object An element of an object dictionary.
Object description Describes data that is communicated over the Fieldbus.
Object Dictionary A structure in a device that describes data that can be communicated
on the Fieldbus. The object dictionary is a lookup table that gives
information such as data type and units about a value that can be read
from or written to a device.
Octet A single 8-bit value.
OD See Object Dictionary.
Offline Not connected to or installed in the computer.
OOS Out of Service mode.
OPC OLE for Process Control.
Output parameter A block parameter that sends data to another block.
P
Parameter One of a set of network-visible values that makes up a function block.
PC Personal Computer.
PCMCIA Personal Computer Memory Card International Association.
PD Proportional Derivative.
PDU Protocol Data Unit.
PID Proportional/Integral/Derivative. A common control function block
algorithm that uses proportions, integrals, and derivatives in
calculation.
PLC See Programmable Logic Controller .
PN Probe Node.
Poll To repeatedly inspect a variable or function block to acquire data.
Port A communications connection on a computer or remote controller.
Process variable A common Fieldbus function block parameter representing some
value in the process being controlled.