Selecting The Control Method - Omron e5ck User Manual

CHAPTER 4 APPLIED OPERATION

4.1 Selecting the Control Method

JHeating and
cooling control
F Dead band
Output
Heating
side
0
Set point
F Cooling
coefficient
4–2
Heating and cooling control is achieved when the control output (cool)"
function is assigned as the output. Discriminately use standard heating
control or cooling control according to the following table:
Parameter
Control Output 1
Control
Method
Heating control
Control output (heat)
(Standard)
Cooling control
Control output (heat)
(Standard)
Heating and cooling
Control output (heat)
control
(Parameters are factory set to heating control.)
• For details on how to assign outputs, see 3.3 Setting Output Specifica
tions (page 3 7).
• When heating and cooling control is selected, the dead band" and cool
ing coefficient" parameters can be used.
The dead band is set with the set point as its center. The dead band width
is the set value of the dead band" parameter (level 1 mode). Setting a posi
tive value produces a dead band, while setting a negative value produces
an overlap band.
The dead band is factory set to 0.00:0.00%FS."
Dead band: dead
band width = positive
Cooling
side
PV
If the heating and cooling characteristics of the control target greatly dif
fer, preventing satisfactory control characteristics from being obtained by
the same PID parameters, adjust the proportional band (P at cooling side)
using the cooling coefficient to balance control between the heating and
cooling sides. In heating and cooling control, P at the heating or cooling
side is calculated by the following formula:
Heating side P = P; Cooling side P = cooling coefficient  P
Control Output 2
Assignment Assignment
Control output (cool)
Output
Heating
side
0
Set point
Direct/Reverse
operations
-
Reverse operation
-
Direct operation
Reverse operation
Overlap band: dead
band width = negative
Cooling
side
PV