Emerson ROC827 Comm Module, Configuration, Tree, Crosstalk, Deadband, Device Directory, Discrete

	ROC827 Instruction Manual
C (continued)
Comm Module	Module that plugs into a ROC to provide a channel for communications via a specified
	communications protocol, such as EIA-422 (RS-422) or HART.
CF	Compare Flag; stores the Signal Value Discrete (SVD).
Configuration	Refers either to the process of setting up the software for a given system or the result of
	performing this process. The configuration activity includes editing the database, building
	schematic displays and reports, and defining user calculations. Typically, the software
	setup of a device that can often be defined and changed. Can also mean the hardware
	assembly scheme.
Configuration	In ROCLINK 800, the graphical display that appears when a configuration file opens. It is
Tree	a hierarchical branching (“tree-style”) method for navigating within the configuration
	screens.
CPU	Central Processing Unit.
CRC	Cyclical Redundancy Check error checking.
Crosstalk	The amount of signal that crosses over between the receive and transmit pairs, and
	signal attenuation, which is the amount of signal loss encountered on the Ethernet
	segment.
CSA	Canadian Standards Association. See http://www.csa.ca.
CSMA/CD	Carrier Sense Multiple Access with Collision Detection.
CTS	Clear to Send modem communications signal.
D
D/A	Digital to Analog signal conversion.
DB	Database.
dB	Decibel. A unit for expressing the ratio of the magnitudes of two electric signals on a
	logarithmic scale.
DCD	Data Carrier Detect modem communications signal. In addition, Discrete Control
	Device – A discrete control device energizes a set of discrete outputs for a given setpoint
	and matches the desired result against a set of discrete inputs (DI).
DCE	Data Communication Equipment.
Deadband	A value that is an inactive zone above the low limits and below the high limits. The
	purpose of the deadband is to prevent a value (such as an alarm) from being set and
	cleared continuously when the input value is oscillating around the specified limit. This
	also prevents the logs or data storage location from being over-filled with data.
Device Directory	In ROCLINK 800, the graphical display that allows navigation through the PC Comm
	Ports and ROC Comm Ports setup screen.
DI	Discrete Input.
Discrete	Input or output that is non-continuous, typically representing two levels (such as on/off).
DMM	Digital multimeter.
DO	Discrete Output.
Download	The process of sending data, a file, or a program from a PC to a ROC.
DP	Differential Pressure.
DSR	Data Set Ready modem communications signal.
DTE	Data Terminal Equipment.
DTR	Data Terminal Ready modem communications signal.
Duty Cycle	Proportion of time during a cycle that a device is activated. A short duty cycle conserves
	power for I/O channels, radios, and so on.
Issued Mar-06	Glossary	A-2