Watlow CLS200 - Manual (Page 233)

CLS200 Series User’s Guide Glossary
Doc.# 0600-3050-2000 Watlow Anafaze 217
Linearity
The deviation in response from an expected or
theoretical straight line value for instruments
and transducers. also called linearity error.
Liquid Crystal Display (LCD)
A type of digital display made of a material
that changes reflectance or transmittance
when an electrical field is applied to it.
Load
The electrical demand of a process, expressed
in power (watts), current (amps) or resistance
(ohms). The item or substance that is to be
heated or cooled.
Loop Alarm
Any alarm system that includes high and low
process, deviation band, deadband, digital out-
puts, and auxiliary control outputs.
Low Deviation Alarm
Warns that the process is below the setpoint,
but above the low process variable. It can be
used as either an alarm or control function.
Low Process Alarm
A signal that is tied to a set minimum value
that can be used as either an alarm or control
function.
Low Reading
An input level corresponding to the low pro-
cess value. For linear inputs, the low reading is
a percentage of the full scale input range. For
pulse inputs, the low reading is expressed in
cycles per second (Hz).
M
Manual Mode
A selectable mode that has no automatic con-
trol aspects. The operator sets output levels.
Manual Reset
See Reset.
Milliampere (mA)
One thousandth of an ampere.
MMI
Man-machine interface.
N
NO-Key Reset
A method for resetting the controller’s memory
(for instance, after an EPROM change).
Noise
Unwanted electrical signals that usually pro-
duce signal interference in sensors and sensor
circuits. See also Electromagnetic Interfer-
ence.
Noise Suppression
The use of components to reduce electrical
interference that is caused by making or
breaking electrical contact, or by inductors.
Nonlinear
Through Anafaze software, the Nonlinear field
sets the system to linear control, or to one of
two nonlinear control options. Input 0 for lin-
ear, 1 or 2 for nonlinear.
O
Offset
The difference in temperature between the set-
point and the actual process temperature. Off-
set is the error in the process variable that is
typical of proportional-only control.
On/Off Control
A method of control that turns the output full
on until setpoint is reached, and then off until
the process error exceeds the hysteresis.
Open Loop
A control system with no sensory feedback.
Operator Menus
The menus accessible from the front panel of a
controller. These menus allow operators to set
or change various control actions or features.
Optical Isolation
Two electronic networks that are connected
through an LED (Light Emitting Diode) and a
photoelectric receiver. There is no electrical
continuity between the two networks.
Output
Control signal action in response to the differ-
ence between setpoint and process variable.
Output Type
The form of PID control output, such as time