Watlow CPC400 - Manual (Page 212)

Glossary CPC400 Series User’s Guide
198 Watlow Anafaze Doc. 0600-2900-2000
portional band and below the cooling propor-
tional band.
Process Hysteresis — In heat/cool applica-
tions, the +/- difference between heat and cool.
Also known as process deadband.
I
Input
Analog Input — An input that accepts pro-
cess variable information.
Digital Input — An input that accepts on and
off signals.
Input Scaling
The converting of input signals to the engineer-
ing units of the process variable.
Input Type
The signal type that is connected to an input,
such as thermocouple, RTD or process.
Integral Control (I)
Control action that automatically eliminates off-
set, or droop, between set point and actual pro-
cess temperature.
J
Job
A set of operating conditions for a process that
can be stored and recalled in a controller’s mem-
ory. Also called a recipe.
Junction
The point where two dissimilar metal conductors
join to form a thermocouple.
K
Keypad Lock
A feature that prevents operation of the keypad
by unauthorized people.
L
Lag
The delay between the output of a signal and the
response of the instrument to which the signal is
sent.
Linearity
The deviation in response from an expected or
theoretical straight line value for instruments
and transducers. Also called linearity error.
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.
Low Deviation Alarm
Warns that the process has dropped more than a
certain amount below set point. It can be used as
either an alarm or control function.
Low Alarm
A signal that is associated with a set minimum
value that can be used as either an alarm or
boost control function.
M
Manual Mode
A selectable mode that has no automatic control
aspects. The operator sets output levels.
Manual Reset
A parameter that allows the user to eliminate off-
set or droop between set point and actual process
temperature. See also Integral.
Milliampere (mA)
One thousandth of an ampere.
N
Noise
Unwanted electrical signals that usually produce
signal interference in sensors and sensor circuits.
See also Electromagnetic Interference.
Noise Suppression
The use of components to reduce electrical inter-
ference that is caused by making or breaking
electrical contact, or by inductors.
O
Offset
The difference between the set point and the
actual value of the process variable. Offset is the
error in the process variable that is typical of pro-
portional-only control.
On/Off Control
A method of control that turns the output full on
until set point is reached, and then off until the
process differs from the set point by more than
the hysteresis.
Open Loop
A control system with no sensory feedback.