Application manual
Air quality multisensor and regulator EK-ES2-TP
Release 1.0 - Updated: 14/02/2020
Application Manual
© EKINEX S.p.A. - All rights reserved
Page 85
9
Control algorithms
In figura sono rappresentati i componenti di un generico sistema di controllo per la temperatura ambiente. Il
termostato rileva il valore attuale di temperatura della massa d’aria ambiente (T
eff
) e la confronta con il valore
di temperatura desiderato o setpoint (T
set
).
The components of a common generic control system for ambient temperature are represented in Picture 11.
The room thermostat measures the actual temperature of the air mass (T
eff
) and constantly compares it to the
setpoint value (T
set
).
Picture 11 - Generic control system for ambient temperature
The control algorithm, basing on the difference between T
set
and T
eff
, processes a command value which can
be of analog or On / Off type; the command is represented by a CO that is transmitted via bus, either
periodically or event based, to a KNX actuator device.
The output of the actuator device is the driving variable of the control system, which can be e.g. a flow rate of
water or air. The control system realized by the room thermostat is of feedback type, namely the algorithm
takes into account the effects on the system in order to change the control action on the same entity.
9.1
Two-point control with hysteresis
This control algorithm, which is also known as On / Off, is the most classic and popular. The control provides
for the on / off switching of the system following a hysteresis loop, i.e. two threshold levels are considered for
the switching instead of a single one (see Picture 12).
Picture 12 - Two-points control with hysteresi
T
eff
Appliance
Solar radiation
Presence of people
Control
algorithm
Actuator
(e.g. relay output
–
valve motor etc)
Heating body
(e.g. radiator, fan-
coil, radiant panel)
Ambient
T
set
+
-
Room thermostat
Actuator control
T ambient
OFF
ON
Tset
Thysteresis
T ambient
OFF
ON
Tset
Thysteresis
Dispersion
