Omron EJ1 User Manual

67
Setting Control Specifications Section 4-3
Heating/Cooling
Control
To perform heating/cooling control, assign the control output (cooling) function
to one of the outputs. For example, when you want to perform heating/cooling
control with channel 1, assign channel 1 control output (cooling) to one of the
outputs.
• Refer to 4-2-1 Control Output Assignments for details on assigning the
control output for cooling.
• The Cooling Coefficient and Dead Band parameters must be set for this
PID control, in addition to the Proportional Band (P), Integral Time (I), and
Derivative Time (D) parameters.
■ Cooling Coefficient
If the heating characteristics and cooling characteristics of the control object
are very different and good control characteristics cannot be achieved with the
same PID constants, the cooling coefficient can be used to adjust the propor-
tional band (P) for the control output assigned to cooling. Use this to achieve
balanced control between the heating side and cooling side.
The proportional bands (P) for the control outputs assigned to the heating/
cooling sides can be calculated using the following equations.
• P for the heating side = P
• P for the cooling side = P for the heating side
× Cooling coefficient
The cooling P is obtained by multiplying the heating P by the cooling coeffi-
cient, so the cooling output control characteristics are different from the heat-
ing output control characteristics.
Note Refer to 4-7-1 Bank Function for details on banks.
■ Dead Band
The dead band is set with the set point as its center.
Setting a negative value produces an overlap band.
Variable type Parameter name Setting range Default
D0/90 Cooling Coefficient (BANK) 0.01 to 99.99 1.00
Conditions for use The control method must be set to heating/cooling control and
2-PID control.
PV
Output
Set point
Heating P
Cooling P
Heating P × 0.8
0
PV
Output
Set point
Heating P
Cooling P
Heating P × 1.5
0
PV
Output
Dead band:
Positive dead band width
Set
p
oint
Heating
side
Cooling side
PV
Output
Overlap band:
Negative dead band width
Set
p
oint
Heating
side
Cooling side

Omron EJ1 Specifications

General

Brand	Omron
Model	EJ1
Category	Temperature Controller
Language	English