36
The limiter will be disabled and settings will not be required under the following
conditions.
•
During manual operation.
•
When a temperature sensor input error or temperature controller error occurs.
•
When operation is stopped.
•
During ON/OFF control.
•
During auto-tuning (applies to the output change rate limiter only).
3-6
Ramp
If the ramp function is enabled and the change in the set point exceeds the speci-
fied rate of change, the set point will change over an interval, as shown in the
following diagram. Temperature will be controlled during the ramp interval ac-
cording to the value limited by this rate of change (i.e., the current set point), and
not by the new set point.
Set point
Set point after
changing
Set point before
changing
Point of change
Ramp interval
Ramp value
Ramp time unit
Time
•
Set the change rate of the ramp interval in each memory bank. The ramp value
and the ramp time unit (hour, minute, or second) must also be set.
•
The setting range is 0.1 to 99.9 (
°
C or
°
F divided by the ramp time unit).The
default is 0.0, i.e., the ramp function is disabled.
The ramp function will be used at the following times.
•
When temperature control is started.
•
When a memory bank number is changed.
•
When the set point is changed.
The ramp function will be ended at the following times.
•
When manual operation is started.
•
When auto-tuning is executed.
If set points and ramp values are reset in memory banks in advance and the
memory bank is switched from the host device over time, the following type of
trapezoidal control will be achieved.
Set point (
°
C)
Memory
bank 0
Memory
bank 1
Memory
bank 2
Time
Limiter Operation
Conditions
Enable Conditions
Disable Conditions
Application Example
Ramp
Section 3-6
