535-PROF User's Manual
Appendix 6
A-19
Glossary
jumper:
A wire that connects or
bypasses a portion of a circuit on the
printed circuit board.
jumper connectors:
The connecting
device that straddles a jumper to
connect or bypass a portion of a circuit
on a printed circuit board.
linearization:
A function the 535 uses
to automatically linearize a non-linear
signal, either from thermocouple or
RTD temperature sensors, through the
use of look up tables. The relationship
that exists between two variables when
the ratio of the value of one variable to
the corresponding value of the other is
constant over an entire range of
possibilities.
linearization, custom:
User-definable
linearization.
linearization, square root:
A function
the 535 uses to linearize a non-linear
signal corresponding to the flow being
measured by flow transmitters.
load line out:
A start up output value
which is to bring initial output closer to
actual steady state output.
Ioop power:
An internal 24-volt current
limited power supply used to power 2
or 4 wire transmitter on the input of the
controller.
load:
The demand for input to a
process.
low pass input filter:
A method to
block fast acting signals (typically
noise), while allowing slow acting
signals (actual process variable) to
pass.
manipulated variable:
A quantity or
condition which is varied so as to
change the value of the controlled
variable. (see also control output)
mechanical relay:
(see relay)
menu:
(see menu block)
menu block:
Groups of parameters
arranged in the software.
microcontroller:
A large scale
integrated circuit that has all the
functions of a computer, including
memory and input/output systems.
NEMA 4X:
A National Electrical
Manufacturers Association standard for
specifying a product’s resistance to
water and corrosion.
normally open:
A switched output (i.e,
relay, etc.) whose unpowered state has
no connection.
normally closed:
A switched output
(i.e., relay) whose unpowered state
provides connection.
noise:
An unwanted component of a
signal or variable.
noise band:
A measurement of the
amount of random process “noise”
affecting the measurement of the
process variable.
offset:
The difference in temperature
between the setpoint and the actual
process temperature. Also, the
adjustment to actual input temperature
and to the temperature values the
controller uses tor display and control.
ON/OFF control:
Control of
temperature about a setpoint by turning
the output full ON below setpoint and
full OFF above setpoint in the heat
mode.
open loop:
Control system with no
sensory feedback.
optimization:
The act of controlling a
process at its maximum possible level
of performance, usually as expressed
in economic terms.
output modules:
Plug in devices that
provide power handling to enable
process control. These modules are
either binary (on/off) such as a relay, or
analog (continuously variable) for
current loop control.
output:
Action in response to difference
between setpoint and process variable.
overshoot:
Condition where
temperature exceeds setpoint due to
initial power up or process changes.
P control:
Proportioning control.
parameter(s):
A user-defined variable
that specifies how a particular function
in the 535 will operate.
PD control:
Proportioning control with
rate action.
PI control:
Proportioning control with
auto-reset.
PID control:
Proportioning control with
auto-reset and rate.
position proportioning:
A type of
control output that utilizes two relays to
control an electric motorized actuator.
POWERBACK®:
Our proprietary
algorithm which monitors the PV to
make predictive judgements to control
parameters in order to reduce or
eliminate overshoot at powerup or after
setpoint changes.
POWERTUNE®:
Our exclusive special
self-tuning function. Consists of an on-
demand pretune that calculates PID
values or provide preliminary PID
values and process information for the
second tuning function. Second tuning
function is an adaptive tuning algorithm
that automatically adjusts PID values
whenever a process upset or setpoint
change occurs.
pretune algorithm:
A method by which
the 535 controller initiates an output
value change, monitors the manner of
the corresponding process variable
change, and then determines the
appropriate PID control parameters.
primary loop:
The outer loop in a
cascade system.
process variable:
In the treatment of
material, any characteristic or
measurable attribute whose value
changes with changes in prevailing
conditions. Common variables are
level, pressure and temperature.
