Nor-Cal SDC15 Controller - Manual (Page 70)

■ Just-FiTTER
This Just-FiTTER function provides the effect of the overshoot suppression and
the following items can be set:
• When the control method is other than the ON/OFF control (CtrL ≠ 0), the
display and setting can be made.
• Function of Just-FiTTER overshoot limit/restraint/control coefficient (JF.ov)
When the Just-FiTTER overshoot limit/restraint/control coefficient (JF.ov) is
“0”, the Just-FiTTER function becomes invalid.
When this coefficient is “1” or more, the effect of the overshoot
limit/restraint/control becomes larger as the coefficient becomes larger.
• Function of Just-FiTTER settling band (JF.bd)
When the % value of the width of the absolute value deviation to the PV range is
larger than the set value, the Just-FiTTER function is started. When this value is
smaller than the set value, this is judged as that the PV is settled by the Just-
FiTTER function.
■ RationaLOOP
This RationaLOOP function suppresses the unstable trend if the immediate
response to external disturbance is increased by the high precision control logic.
The following items can be set:
• When the control method is other than the ON/OFF control (CtrL ≠ 0), the
display and setting can be made.
■ SP lag
This SP lag function suppresses changes in MV when the SP is changed. The
following items can be set:
• When the control method is other than the ON/OFF control (CtrL ≠ 0), the
display and setting can be made.
• Function of SP lag time (SP.Lg)
When the SP lag time is set at "0.0", the SP lag function becomes invalid.
When this value is "0.1" or more, changes in MV when the SP is changed
become smaller and the effect of the overshoot suppression becomes larger as the
value becomes larger.
5-20
Chapter 5. DETAILED DESCRIPTION OF EACH FUNCTION
Item (Setting display/bank) Display Contents Initial value User level
Just-FiTTER overshoot
limit/restraint/control
coefficient
(Parameter setup/Extended
tuning bank) 0 to 100
(No JF function when set at “0”.) 0 Standard,
High function
Just-FiTTER settling band
(Parameter setup/Extended
tuning bank) 0.00 to 10.00% 0.30% High function
Item (Setting display/bank) Display Contents Initial value User level
Control algorithm
(Parameter setup/Extended
tuning bank) 0: PID (Conventional PID)
1: RationaLOOP (High-performance PID) 0 Standard,
High function
Item (Setting display/bank) Display Contents Initial value User level
SP lag time
(Parameter setup/Extended
tuning bank) 0.0 to 999.9
(No effect when set at “0.0”.) 0.0 High function