Disclaimer; Copyright - gefran 3850T Use And Installation Manual

system, meaning a device whose input
acquires a value from a process, compares
it with a reference value and uses the
difference (error) for determine the value
of the controller output variable, which is
the variable that controls the process itself.
The output is controlled according to the
actual error value (proportional action), a
set of previous error values (integral action)
and the error value rate of change (deriva-
tive action).
Setpoint Profile See SP.
Program Function set (Sp Profile, Sequential Logic,
Recording) that describe a production cycle.
Pt100 Commonly used temperature probe.
At 0° C /F, its resistance is 100 ohms, while
at room temperature is about 106 ohms.
You can test the Pt100 for electrical con-
tinuity and you can use normal extension
cords.
PV Acronym for Process Value, which is the
value that the process variable (tem-
perature, valve opening, etc.) has at that
moment.
Solid State
Relay Also known as SSR (Solid-state relay) is
a relay designed specially for frequent
switching. There are no moving parts
or mechanical contacts, but may, however,
fail or short circuit. These types of relays
are often used in temperature control
systems such as PID.
Segment
Basic element for the configuration of a
SP profile. It describes the operations of
an individual segment in detail. The set of
segments describes the execution of a SP
profile.

Disclaimer

Although all information contained within this document has
been carefully checked, Gefran S.p.A. cannot be held liable
for the possible presence of errors, or damage to persons
or property due to improper use of this manual.
Gefran S.p.A. also reserves the right to make changes
to the content and form of this document as well as the
characteristics of the illustrated devices at any time without
prior notice.

Copyright

This document and its annexes may be freely reproduced,
provided that the contents are not modified in any way
and each copy includes this warning and the statement of
Gefran S.p.A. ownership.
80703B_MHW_2850T/3850T_02-2019_ENG
Sensor A device that translates physical phenom-
ena (i.e. resistance variation as a function
of temperature) in electrical signals that
can be acquired and processed by the
controller.
Setpoint
Set value (see SV).
SSP
SP/FSSPActive set point, in the case of a
set point gradient, shows its real value.
SP Acronym for Setpoint Profile meaning the
set of segments that describe the trend
over time of a value, typically a setpoint
and the status of a series of digital events
(In/Out).
SV Acronym for Set Value which is the value
that the process variable (temperature,
valve opening, etc.) must achieve and
maintain.
TA
Current transformer
Thermocouple Sensor that transmits an electrical signal
of a few millivolts, that cannot be tested
for electrical continuity.
It needs specially designed extension
cords.
Undershoot Situation where PV does not reach SV
because the control action was too early.
The ON-OFF controls have an undershoot
greater than the PID controls.
Engineering unit Unit of measure suited to directly express
the measured physical variable value.
Control output Output that controls the process and is
turned on and off as needed.
The technical and performance data indicated in this
manual are to be considered as a guide for the user to
determine the suitability for a certain use, and are not
guarantees. They may be the result of Gefran S.p.A. test
conditions and the user must compare them to his/her real
application requirements.
Gefran S.p.A. cannot be held in any way liable for any dam-
age to persons or property resulting from controller tamper-
ing, incorrect and improper use or otherwise non compliant
with controller features and instructions in this manual.
Gefran and GF_eXpress are trademarks of Gefran S.p.A.
The document may mention or reproduce trademarks and
logos of third parties. Gefran S.p.A. acknowledges the owner-
ship of these trademarks or logos by their respective owners.
PREFACE
7