YOKOGAWA UP35A, User Manual

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8-12
IM 05P02D41-01EN
8.2.3 Heating/cooling Control
Description
Heating/cooling control can be used only for Heating/cooling type.
In Heating/cooling control, the controller outputs the result of computation after splitting it
into heating-purpose and cooling-purpose signals. PID control or ON/OFF control can be
selected for each of the heating side and the cooling side.
Set the heating-side proportional band to “0” to perform ON/OFF control on the heating
side. Set the cooling-side proportional band to “0” to perform ON/OFF control on the
cooling side.
Control computation
0 to 100 %
Heating/cooling computation
0 to 50 %
Cooling-side output limiter
Cooling-side control output
0 to 100 %
Heating-side control output
0 to 100 %
50 to 100%
Heating-side output limiter
PV SP
Manual control output
COM
Details of Heating/cooling Control
In Heating/cooling control, PID control or ON/OFF control can be selected for each of the
heating side and the cooling side.
Set the proportional band to “0” to perform ON/OFF control.
The following describes the combination of heating side and cooling side.
When Both the Heating Side and Cooling Side are in PID Control
The following shows the formula and operation example.
HOUT = ( OUT – – 50% ) × 2
2
DB
*: OUT: control output, HOUT: heating-side control output,
COUT: cooling-side control output, P: heating-side proportional band,
Pc: cooling-side proportional band, and DB: dead band
COUT = ( 50% – OUT – ) × 2 ×
2
DB
Pc
P
8.2 Setting Control Type (CNT)