Fourth value (fv) – Rockwell Automation 1756-OF8H ControlLogix HART Analog I/O Modules User Manual
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Rockwell Automation Publication 1756-UM533C-EN-P - February 2011
Glossary
exact match
An Electronic Keying Protection mode that requires the physical module and the
module configured in the software to match identically, according to vendor,
catalog number, major revision, and minor revision.
field side
Interface between user field wiring and I/O module. In this glossary, see related
entry for system side.
flash update
The process of updating the firmware of the module.
fourth value (FV)
Also abbreviated as QV for quaternary value, this dynamic variable contains the
fourth value of Device Variables, which are direct or indirect process
measurements by a HART field device.
frequency shift keying
A method of using frequency modulation to send digital information used by
HART field devices.
Hard Run mode
Mode where keyswitch of controller is in Run position.
HART
Acronym for highway addressable remote transducer.
inhibit
A ControlLogix process that lets you configure an I/O module, but prevent it
from communicating with the owner-controller. In this case, the controller does
not establish a connection.
Input Data format
Format that defines the type of information transferred between an I/O module
and its owner-controller. This format also defines the tags created for each I/O
module.
interface module (IFM)
A pre-wired removable terminal block (RTB).
listen-only connection
An I/O connection that lets a controller monitor I/O module data without
owning the module, sending it a configuration, or controlling its outputs.
major revision
A module revision that is updated any time there is a functional change to the
module, resulting in an interface change with software.
minor revision
A module revision that is updated any time there is a change to the module that
does not affect its function or software user interface.
multicast
Data transmissions which reach a specific group of one or more destinations.
multiple owners
A configuration setup where multiple owner-controllers use exactly the same
configuration information to simultaneously own an input module.
network update time (NUT)
The smallest repetitive time interval in which the data can be sent on a
ControlNet network. The NUT can be configured over the range from 2…100
ms using RSNetWorx software.