Omron EJ1 User Manual page 106

Setting Control Specifications
Note
!Caution
RT (Robust Tuning)
1. The previous SRT-implemented set point is the set point that was used for
calculating the PID constants for the previous SRT.
2. In this state, the measurement point is within the ST stable range.
3. In this state, the change width of the PV every 60 seconds is at the ST sta-
ble range or less.
In the following instances, PID constants are not changed by self-tuning (ST)
for the present set point.
1. When the PID constants have been changed with ST enabled.
2. When autotuning (AT) has been executed.
3. When switching banks while starting ST.
Stop self-tuning (ST) (PID constants are not changed). ST will not start
even for banks that have been switched.
When banks have been switched, ST will be implemented for every bank
when first operated. After the first operation, ST will not be implemented until
the set points of selected banks have been changed.
SP = 200
SP = 100
ST is executed
Bank 0
When ST is enabled, the following functions will be disabled.
SP ramp
MV limiter
While SRT is executing, the Disturbance Overshoot Adjustment Function
will be disabled.
When using this function, set the following parameters to their default set-
tings: Output Scaling Upper Limit 1 to 4, Output Scaling Lower Limit 1 to 4,
and Decimal Point C1 to C4. If these parameters are set to anything other
than their defaults, ST will not operate properly.
Switching to manual mode while ST is operating will cause ST to stop.
When using ST, do not use MV calculation on the G3ZA.
When autotuning or self-tuning
stants are automatically set that make it hard for control performance to
degenerate even when control object's characteristics change.
• Selecting the RT mode in the following cases will help to prevent hunting
from occurring.
• When the set temperature is not fixed and is changed in a wide range
• When there are large variations in ambient temperatures due to factors
such as seasonal changes or differences between day and night tem-
peratures
• When there are large variations in ambient wind conditions and air flow
• When heater characteristics change depending on the temperature
ST is executed
ST is not executed
Bank 1 Bank 0
is executed with RT selected, PID con-
V1.2
Section 4-3
ST is not executed
Bank 1
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