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3.3.5
Other Setup Required
- O1TY, CYC1, O2TY, CYC2, O1FT, O2FT O1TY & O2TY are set in accordance with the type of outputs
(OUT1 & OUT2) installed.
- CYC1 & CYC2 are set according to the output 1 type (O1TY) & output 2 type (O2TY).
Generally, if “SSRD” or “SSR” is used for O1TY, CYC1 is set to a value of 0.5 - 2 seconds. If a Relay is used
for O1TY, CYC1 is set to a value of 10 - 20 seconds .If a linear output is used, CYC1 is not applicable.
Similar conditions are applied for CYC2 selection.
The user can use the Auto-Tuning feature for initial start-up, or they can directly set the appropriate values for
PB, TI & TD using the historical records for repeat systems. If the control behavior is still inadequate, then
manual tuning may be required to improve control.
3.3.6
CPB Programming
The cooling proportional band is measured by % of PB with a range of 50~300%. Initially, set
“CPB” to 100% and examine the cooling effect. If the cooling action should be enhanced, decrease the CPB
value. If the cooling action is too strong, increase the CPB value. The value of CPB is directly proportional to
the PB setting. Its value remains unchanged throughout the Auto-Tuning process.
Adjustment of CPB is related to the cooling medium used. If air is used as a cooling medium,
set the CPB to 100(%). If oil is used as the cooling medium, set the CPB to 125(%). If water is used as the
cooling medium, set the CPB to 250(%).
3.3.7
DB Programming
Adjustment of DB (Dead band) is dependent on system requirements. If a greater dead
band is used, then an unwanted cooling action can be avoided, but an excessive overshoot or oscillation
around the set point can occur. If a smaller dead band (DB) is used, then an excessive overshoot can be
minimized, but an overlapping of the heating and cooling action will occur. The DB setting is adjustable in the
range of -36.0% to 36.0 % of PB.
A negative DB value will have an overlap where both outputs are active. A positive DB value
has a dead band area where neither output is active.
3.3.8
Output 2 ON-OFF Control (Alarm function)
Output 2 can also be configured as an alarm output. There are 8 kinds of alarm functions
and a Dwell timer (dtMR) that can be selected for output 2.
The output options are:
-
dtMR (Dwell Timer)
-
dE.HI (deviation high alarm)
-
dE.Lo (deviation low alarm)
-
dB.Hi (Out of band alarm)
-
dB.Lo (In band Alarm)
-
PV.HI (process value high alarm)
-
PV.LO (process value low alarm)
-
H.bK (Heater Break Alarm)
-
And H.St (Heater Short Alarm).
