GVS K-BUS
○
R
KNX/EIB
Thermostat
www.video-star.com.cn
marketing@video-star.com.cn
Tel.
:
(
8620
)
39338986
Fax.
:(
8620
)
39338465
38
Parameter “control parameter of cooling system”
Options
:
Cooling ceiling (5K/240min)
Split unit (4K/90min)
PI auto tuning
User-defined parameter
If the option is "PI auto tuning", you can obtain the PI parameters through auto tuning. After
programming the Thermostat starts auto-tuning, makes room temperature oscillate upper and lower
around temperature setpoint through fully open and fully close operations. After two oscillation cycles, PI
parameters will be calculated according to the amplitude and period of oscillation waveform. Finally, the
the self-tuning state ends and turns to PI control state, which controls according to the parameters got
from auto tuning. When the bus turns off and then turns on PI continues to control according to those
parameters. The period of Self-tuning ranges from tens of minutes to several hours depending on the
controlled object. Parameters got from PI auto tuning may not be optimal.During the process of PI auto
tuning, please do not adjust temperature setpoint, or convert heating and refrigeration to prevent
interference of PI auto tuning.
In the option of "user-defined parameter", PI parameter values can be set through the following two
parameters and application of Thermostat will calculate the control value basing on the given parameter
values.
PI parameter values of other options are specified.
Parameter "proportional range (× 0.1
℃
)"
Options: 10 ... 100
In the parameter "control parameter of heating / cooling system",when the option is "user-defined
parameter", this parameter is visible and is used to set parameter values of P (proportional band) with
the unit is
℃
. Proportional factor equals to 255 divided by ratio range. The proper ratio range must be
appropriately set. If it is too small it will cause very fast adjustment and overshoot.If it is too large it will
cause very slow adjustment,but not overshoot. For example: the ratio range is 5
℃
, when temperature
deviation is 2
℃
,proportional control value will be(255/5) * 2 = 102. PI control value equals proportional
control value plus integral term control value.
Parameters "reset time (min)"