Omron EJ1G User Manual page 98

Setting Control Specifications
Autotuning (AT)
GT Natural Cooling Time
Channel outputs within a group turn ON in order during GT. The time from
when one output turns OFF until the next output turns ON can be adjusted
using the GT Natural Cooling Time parameter.
If here is a period where the temperature for the previous channel has not
returned to room temperature by the time the next output turns ON, increase
the setting for the GT Natural Cooling Time. If, on the other hand, channels
immediately return to room temperature in all periods, then shorten the GT
Natural Cooling Time. This will shorten the execution time for GT.
GT Stabilization Band
If the temperature of a channel increases by more than the value set for the
GT Stabilization Band parameter after the output turns ON, the increase is
treated as the effect of interference.
When autotuning (AT) is executed, the MV is forcibly changed, the control
subject's characteristics are observed (with the limit cycle method), and the
best PID constants are automatically set for the SP during execution.
• Autotuning cannot be executed while control is stopped, during manual
mode operation, or during ON/OFF control.
• Use an operation command to execute autotuning. For details, refer to 6-
4-11 Operation Commands.
• The only parameters that can be received during autotuning are RUN/
STOP, Auto/Manual, AT Execute/Cancel, Alarm 1/2/3 Latch Cancel, and
Alarm Latch Cancel All. Other parameters cannot be changed.
• If the STOP parameter is set during autotuning, autotuning will be can-
celled and operation will stop. Autotuning will not be restarted even if RUN
is set again.
• Normally the following parameters are left at their default settings.
Variable type
E5/A5
Conditions for use
Note (1) This parameter can be set only when operation is stopped.
(2) The decimal point position is determined by the sensor selection. With
analog inputs, the decimal point position is determined by the Decimal
Point Position parameter setting. In this case, however, the 0 (****) deci-
mal point position setting will be treated as setting 1 (***.*).
AT Calculated Gain
Sets the gain used when calculating the PID constants in autotuning. When
emphasizing flexibility, decrease the set value. When emphasizing stability,
increase the set value.
AT Hysteresis
The limit cycle operation during autotuning has a hysteresis when switching
ON and OFF. This parameter sets that hysteresis value.
Parameter name
AT Calculated Gain
AT Hysteresis
Limit Cycle MV Amplitude
Temporary AT Execution Judgment Deviation
The control method must be set to standard control and 2-PID
control.
Section 5-3
Setting range Default
(Common) 0.1 to 10.0
(Channel) 0.1 to 999.9 EU
(See note 2.)
(Common) 5.0 to 50.0%
0.0 to 999.9 EU
(Channel) (See note 2.)
0.8
0.8
20.0
150.0
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