User`s manual

535 User's Manual Appendix 6 A-19
Glossary
FM: Factory Mutual Research
Corporation; an organization
which sets safety standards.
gain: The ratio of the change in
output to the change in input which
caused it.
heat/cool control: Control method
where the temperature of the end
product is maintained by controlling
two final elements using two of the
535 outputs.
hysteresis: In ON/OFF control, the
temperature change necessary to
change the output from full ON to
full OFF.
hunting: Oscillation or fluctuation
of process temperature between
setpoint and process variable.
icons: Indicators on the face of the
controller.
input: Process variable information
being supplied to the instrument.
integral: Control action that
automatically eliminates offset, or
“droop”, between setpoint and actual
process temperature. Also “reset.”
internal voltage reference: A
precision voltage source within the
535 controller, used to establish
internal calibration.
isolation: Electrical separation of
sensor from high voltage circuitry.
Allows for application of grounded or
ungrounded sensing element.
offset: Adjustment to actual input
temperature and to the temperature
values the controller uses tor display
and control.
JIS: Japanese Industrial Standards.
Also Japanese Industrial Standards
Committee (JISC). Establishes
standards on equipment and
components.
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.
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