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65
Setting Control Specifications
Section 4-3
4-3-2
Selecting the Control Method
The control method can be set to either 2-PID control or ON/OFF control.
Note
This parameter can be set only when operation is stopped.
ON/OFF Control
In ON/OFF control, the control output turns OFF when the currently controlled
temperature reaches a preset set point. When the manipulated variable turns
OFF, the temperature begins to fall and the control output is turned ON again.
This operation is repeated at a certain level. The Hysteresis (Heating) param-
eter determines how much the temperature must fall before the control output
is turned ON again. Also, the Direct/Reverse Operation parameter determines
whether the manipulated variable is increased or decreased in response to an
increase or decrease in the process value.
■
Hysteresis
ON/OFF control incorporates a hysteresis setting to stabilize operation when
switching ON and OFF. The width of the hysteresis loop determines the sensi-
tivity.
• The control output (heating) and control output (cooling) hysteresis set-
tings are made with the Hysteresis (Heating) and Hysteresis (Cooling)
parameters, respectively.
• The sensitivity of standard control (heating or cooling) is set with the Hys-
teresis (Heating) parameter, regardless of the setting of the Direct/
Reverse Operation parameter.
• The Hysteresis (Cooling) parameter is effective only when using heating/
cooling control.
Note
The decimal point position is determined by the sensor selection. In this case,
however, the 0 (****) decimal point position setting will be treated as setting 1
(***.*).
Variable type
Parameter name
Setting range
Default
E5/A5
PID/OnOff (Channel)
0: 2-PID control
1: ON/OFF control
0
Conditions for use
No special conditions
Variable type
Parameter name
Setting range
Default
D5/95
Hysteresis (Heating)
(Channel) 0.1 to 999.9 EU
1.0
Hysteresis (Cooling)
(Channel) 0.1 to 999.9 EU
1.0
Conditions for use
The control method must be set to ON/OFF control.
Hysteresis (Heating)
Set point
OFF
ON
PV
Heating control
Hysteresis (Cooling)
Set point
OFF
ON
PV
Cooling control
Summary of Contents for EJ1 EtherCAT
Page 2: ...EJ1 Modular Temperature Controllers User s Manual Revised July 2008 ...
Page 3: ...iv ...
Page 19: ...xx ...
Page 213: ...188 Detailed Description of Services Section 6 4 ...
Page 227: ...202 Detailed Description of Services Section 7 5 ...
Page 303: ...278 Index ...
Page 305: ......