Sp Ramp Function: Limiting Sp Change Rate; Sp Ramp - Omron E5ZN Operation Manual

SP Ramp Function: Limiting SP Change Rate

4-7

SP Ramp Function: Limiting SP Change Rate

4-7-1

SP Ramp

SP after change
SP before change
Operation at Start
SP
Set point
PV
Restrictions during SP
Ramp Operation
The SP ramp function controls the rate of change of the set point. If a change
larger than the rate of change is specified when the SP ramp function has
been enable, changes in the set point will be limited as shown below. Thus,
when changes are made to the set point with the SP ramp function enabled,
control is performed according to the rate of change rather than the target
value.
SP
Change point
The change rate during SP ramp is specified in the "SP ramp set value"
parameter. The "SP ramp set value" default is 0, i.e., the SP ramp function is
disabled.
The ramp set point can be monitored in the "Set point during SP ramp"
parameter.
When the power is turned ON, operation is performed with the process value
treated as the set point before the change was made.
The direction of the SP ramp changes according to the relationship between
the process value and the set point, as shown in the following diagram.
PV < SP
SP ramp
Power ON
• Autotuning starts after the SP ramp function ends.
• When control is stopped or an error occurs, the SP ramp function is dis-
abled.
SP ramp
SP
PV
Set point
Time
Power ON
Section 4-7
SP ramp set value
Time unit of SP ramp rate (min.)
Time
PV > SP
SP ramp
Same change rate
Time
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