Glossary
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National Instruments Corporation
G-7
Physical Layer
The layer of the communication stack that converts digital Fieldbus
messages from the communication stack to actual physical signals on
the Fieldbus transmission medium and vice versa.
PLC
See
Programmable Logic Controller.
Poll
To repeatedly inspect a variable or function block to acquire data.
Port
A communications connection on a computer or remote controller.
Program
A set of instructions the computer can follow, usually in a binary file
format, such as a
.exe
file.
Programmable Logic
Controller
A device with multiple inputs and outputs that contains a program
you can alter.
R
Repeater
Boost the signals to and from the further link.
Resource block
A special block containing parameters that describe the operation
of the device and general characteristics of a device, such as
manufacturer and device name. Only one resource block per device
is allowed.
Roundcard
A hardware interface for developing Foundation Fieldbus-compliant
devices.
S
s
Seconds.
Segment
See
.
Sensor
A device that responds to a physical stimulus (heat, light, sound,
pressure, motion, flow, and so on), and produces a corresponding
electrical signal.
Server
Device that receives a message request.
Session
A communication path between an application and the NI-FBUS
Communications Manager.
Shield
Metal grounded cover used to protect a wire, component or piece of
equipment from stray magnetic and/or electric fields.
