Using On/Off Control (Not Supported For Position-Proportional Models.); On/Off Control - Omron E5C User Manual

4-8 Using ON/OFF Control (Not
Supported for Position-proportional
Models.)
In ON/OFF control, the control output turns OFF when the temperature being controlled reaches the
preset set point. When the manipulated variable turns OFF, the temperature begins to fall and the con-
trol turns ON again. This operation is repeated over a certain temperature range. At this time, how
much the temperature must fall before control turns ON again is determined by the Hysteresis (Heating)
parameter. Also, what direction the manipulated variable must be adjusted in response to an increase
or decrease in the process value is determined by the Direct/Reverse Operation parameter.
4-8-1

ON/OFF Control

• Switching between 2-PID control and ON/OFF control is performed using the PID ON/OFF parameter
in the Initial Setting Level. When this parameter is set to pid, 2-PID control is selected, and when it is
set to onof, ON/OFF control is selected. The default is onof.
Hysteresis
• With ON/OFF control, hysteresis is used to stabilize operation when switching between ON and
OFF. The control output (heating) and control output (cooling) functions are set in the Hysteresis
(Heating) and Hysteresis (Cooling) parameters, respectively.
• In standard control (heating or cooling control), the setting of the Hysteresis (Heating) parameter
in the Adjustment Level is used as the hysteresis regardless of whether the control type is heating
control or cooling control.
Reverse operation
Temperature
SP
0
Heater
E5@C Digital Temperature Controllers User's Manual (H174)
ON OFF ON OFF
Hysteresis
Time
ON OFF ON
4 Basic Operation
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