EZT-570S User Manual
A.2
Common Terms and Definitions
Autotune
— A feature that automatically sets process control PID values to match a particular
process in a system.
Baud rate
— The rate of information transfer in serial communications, measured in bits per second.
Accuracy
— Closeness between the value indicated by a measuring instrument and a physical
constant or known standard.
Offset
— An adjustment to eliminate the difference between the indicated value and the actual
process value.
Cascade
— Control algorithm in which the output of one control loop provides the set point for
another loop. The second loop, in turn, determines the control action.
Derivative control (D)
— The last term in the PID control algorithm. Action that anticipates the rate
of change of the process, and compensates to minimize overshoot and undershoot. Derivative control
is an instantaneous change of the control output in the same direction as the proportional error. This
is caused by a change in the process variable (PV) that decreases over the time of the derivative
(TD). The TD is in units of seconds.
DHCP (Dynamic Host Configuration protocol)
— Permits auto-assignment of temporary IP
addresses for new devices logging in to the network.
DNS (Domain Name Server)
— Associates names with IP addresses over a network.
Droop
— In proportional controllers, the difference between set point and actual value after the
system stabilizes.
EIA
— See Electronics Industries of America.
EIA/TIA -232 and -485
— Data communications standards set by the Electronic Industries of America
and Telecommunications Industry Association. Formerly referred to as RS- (Recognized Standard).
Electronics Industries of America (EIA)
— An association in the US that establishes standards for
electronics and data communications.
FTP (File Transfer Protocol)
—
The most popular mechanism for bulk movement of files on TCP/IP.
Fuzzy logic
— A mathematical control algorithm that monitors past response of a system to predict
future response and automatically adjust PID parameters in order to adapt to process.
Hysteresis
— A change in the process variable required to re-energize the control or alarm output.
Sometimes called switching differential.
Integral control (I)
— Control action that automatically eliminates offset, or droop, between set point
and actual process temperature.
IP Address
— Address of a TCP/IP enabled device on an Intranet or Internet.
LAN (Local Area Network)
— A group of computers and associated devices that share a common
communications line or wireless link.
Summary of Contents for EZT-570S
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