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Note
The ON-OFF control may result excessive overshoot and undershoot problems in the process.
The P (or PD) control will result in a deviation process value from the set point. It is recommended to use
PID control for the Heat-Cool control to produce a stable and zero offset process value.
Other Setup Required
O1TY, CYC1, O2TY, CYC2, A2SP, A2DV, O1TY & O2TY are set in accordance with the types
of OUT1 & OUT2 installed. CYC1 & CYC2 are selected according to the output 1 type ( O1TY ) & output 2
type ( O2TY ).Generally, selects 0.5 ~ 2 sec. for CYC1, if SSRD or SSR is used for O1TY; 10 ~ 20 sec. if
relay is used for O1TY, and CYC1 is ignored if linear output is used. Similar condition is applied for CYC2
selection.
Examples
Heat PID+Cool ON-OFF: Set OUT1= REVR, A1FN or A2FN= PV1.H, A1FN or A2MD=NORM,
A1HY or A2HY=0.1, PB1=0, TI1=0, TD1=0, and set appropriate values for O1TY and CYC1.
Heat PID+Cool PID: set OUT1=REVR, OUT2=COOL, CPB=100, DB=-4.0, PB1=0, TI1=0,
TD1=0, and set appropriate values for O1TY, CYC1, O2TY, and CYC2.
CPB Programming
The cooling proportional band is measured by % of PB with range 1~255. Initially set 100% for
CPB and examine the cooling effect. If cooling action should be enhanced then decrease CPB .If cooling
action is too strong then increase CPB. The value of CPB is related to PB and its value remains unchanged
throughout the self-tuning and auto-tuning procedures.
Adjustment of CPB is related to the cooling media used. For air is used as cooling media, adjust
CPB at 100(%). For oil is used as cooling media, adjust CPB at 125(%). For water is used as cooling media,
adjust CPB at 250(%)
DB Programming
Adjustment of DB is dependent on the system requirements. If more positive value of DB
(greater dead band) is used, an unwanted cooling action can be avoided but an excessive overshoot over
the set point will occur. If more negative value of DB (greater overlap) is used, an excessive overshoot over
the set point can be minimized but an unwanted cooling action will occur. It is adjustable in the range -
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