Despatch MIC1462 Controller Manual - Manual (Page 43)

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SECTION 5: USING THE PRETUNE AND AUTOTUNE FEATURES
5.1 Using The Pre-Tune Facility
The Pre-Tune facility is used to set the instrument's PID control parameters to values
which are approximately correct in order to provide a base from which the Auto-Tune
facility may subsequently optimize tuning. Pre-Tune may be activated as follows:
1. With the instrument in Base mode (with the RUN and HLD indicators off), press the
MODE key until the Message Display reads PreTune and the lower Main Display
shows reads OFF.
2. Press the UP key to change the lower Main Display to ON, indicating that the Pre-
Tune facility is now activated. The AT indicator will flash.
NOTES:
1. If the process variable is within 5% of the input span from the setpoint, the
Pre-Tune facility cannot be activated and any attempt to do so will have no
effect.
2. Since the Pre-Tune facility is a single-shot operation., it will automatically de-
activate itself once the operation is complete.
To de-activate the Pre-Tune facility manually (with the instrument in Base Mode),
access the Pre-Tune mode using the instructions above; then press the DOWN key to
change the lower Main display from ON to OFF.
5.2 Using The Auto-Tune Facility
The Self-Tune facility is used to optimize tuning while the Controller part of the
instrument is operating. Auto-Tune may be activated as follows:
1. With the instrument in Base Mode (with RUN and HLD indicators OFF), press the
MODE key until the Message Display reads AutoTune and the lower Main Display
reads OFF.
2. Press the UP key to change the lower Main Display to ON, indicating that the Auto-
Tune facility is now activated. The AT indicator is on continuously.
To de-activate the Auto-Tune facility, access the Auto-Tune mode using the instructions
above, then press the DOWN key to change the lower Main Display from ON to OFF.