8. ENGINEERING MODE
IMR01N12-E7
96
AT action (1. ATt, 2. ATt)
Use to select the Autotuning (AT) function.
Data range:
0: AT function (PID)
(AT result is reflected to derivative time.)
1: AT function (PI)
(No AT result is reflected to derivative time.)
2: No AT function
Factory set value:
Input 1_AT action (1. ATt): 2
Input 2_AT action (2. ATt): 2
Related parameters:
PID/AT transfer (P. 101)
Autotuning (AT) function:
Autotuning (AT) automatically measures, calculates and sets the optimum PID (PI)
constants. The following conditions are necessary to carry out autotuning and the
conditions which will cause the autotuning to stop.
AT start
First, select the AT function type on the AT action selecting screen. Next, check that all
of the following conditions are satisfied. The autotuning (AT) is executed on the PID/AT
transfer screen in RUN mode. (Refer to P. 101)
Operation mode conditions are as follows:
Auto/Manual transfer
→
Auto mode
Remote/Local transfer
→
Local mode
PID/AT transfer
→
PID control
RUN/STOP transfer
→
Control RUN
The Measured value (PV) is without input error range [Input error determination point
(high) > Measured value (PV) > Input error determination point (low)].
The Output limiter high is 0.1 % or higher and the Output limiter low is 99.9 % or less.
When the Autotuning is finished, the controller will automatically returns to PID
(PI) control.
AT cancellation
The Autotuning is canceled if any of the following conditions exist.
When the Temperature set value (SV) is changed.
When the Output limiter high or the Output limiter low is changed.
When the PV bias, the PV digital filter, or the PV ratio is changed.
When the Auto/Manual mode is changed to the Manual mode.
When the Remote/Local mode is changed to the Remote mode.
When the Measured value (PV) goes to input error range [Measured value (PV)
Input error determination point (high) or Input error determination point (low)
Measured value (PV)].
When the power failure occurs.
When the instrument is in the FAIL state.
When the PID/AT transfer is changed to the PID control.
When the RUN/STOP mode is changed to the control STOP.
If the AT is canceled, the controller immediately changes to PID (PI) control.
The PID (PI) values will be the same as before AT was activated.
