CHAPTER 4 APPLIED OPERATIO N
E5EK
4--4
• Switching b etween advanced PID control and ON/OFF control is car-
ried out by the “PID / ON/OFF” parameter (expansion mode). When
this parameter is set to [
], advanced PID control is selected, and
when set to [
], ON/OFF control is selected. Default is [ ].
• During position-proportional control, ON/OFF control cannot be
selected.
• In ON/OFF control, hysteresis is provided in the program when
switching between ON and OFF to stabilize operation. The hysteresis
width provided during ON/OFF control is simply referred to as “hys-
teresis.” Control output (heat) and control output (cool) functions are
set in the “hysteresis (heat)” and “hysteresis (cool)” parameters, re-
spectively.
• In standard control (heating or cooling control), hysteresis can be set
only for the heating side.
ON
OFF
PV
Hysteresis (heat)
Set point
• In heating and cooling control, a dead b and can be set. So, 3-position
control is made possible.
ON
OFF
PV
Hysteresis (heat)
Heating
side
Set point
Cooling side
Hysteresis (cool)
Dead band
Symbol
Parameter Name: Mode Description
Control output 1
assignment : Setup
For specifying control method
Control output 2
assignment : Setup
For specifying control method
Direct/Reverse
operation : Setup
For specifying control method
Dead band : Level 1 Heating and cooling control
Cooling coefficient : Level 1 Heating and cooling control
MV at stop : Level 2 Manipulated variable when control
operation is stopped
MV at PV error : Level 2 Manipulated variable when control
operation is PV error
Travel time : Option Position-proportional control
Motor calibration : Option Position-proportional control
Positional-proportional
dead band : Level 1
Position-proportional control
Open/close
hysteresis : Level 2
Position-proportional control
Hysteresis (heat) : Level 1 ON/OFF control
Hysteresis (cool) : Level 1 ON/OFF control
PID / ON/OFF : Expansion ON/OFF control
JON/OFF control
F Hysteresis
Parameters
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