40
•
When switching between manual operation and 2-PID control, the output val-
ue will enter balanceless, bumpless operation.
Output value (%)
Balanceless, bumpless
operation
Time
0
Output reset value
Output switch
Manual operation
2-PID control
Power OFF or operation
stopped
Operating Conditions
•
The manual output value can be set only during manual operation. The manual
output value cannot be set if there is a temperature sensor input error or a Tem-
perature Controller error.
•
Manual operation cannot be started if auto-tuning is being executed or there is
a Temperature Controller error.
•
The E5ZE-8
D1
B (DeviceNet Model) cannot be operated manually if
operation has been stopped. Temperature control must be started with remote
I/O before manual operation can be started. For further details, refer to the
E5ZE-8 Multipoint Temperature Controller DeviceNet Communications Manu-
al (H104).
3-8-2 ON/OFF Control
2-PID control can be switched to ON/OFF control by setting the proportional
band (P constant) to 0.0.
In ON/OFF control, hysteresis is used to stabilize operation when a change is
made to ON/OFF control. The following diagrams show the operation of control
output during ON/OFF control.
Reverse operation
Direct operation
Hysteresis
Hysteresis
Set point
Set point
•
Set the hysteresis in each memory bank. The settings are only valid when ON/
OFF control is being used.
•
The setting range is between 0.0 to 99.9 (
°
C or
°
F).
•
The default value is 0.8
°
C or 1.5
°
F.
Hysteresis
Control Method Selection
Section 3-8
