MIC 1400 Manual
Edition 1
31
Pre-Tune Mode 3.3
The Pre-Tune mode may be used to set the instrument's PID parameters to
values which are approximately correct, in order to provide a base from
which the Auto Tune mode may optimize tuning.
To engage the Pre-Tune mode, with the instrument in Control mode, press
and hold the UP and DOWN keys for approximately 5 seconds (the display
will flash during this period) until the AT LED flashes once. Release the UP
and DOWN keys. Press and hold the SCROLL key for approximately 3
seconds until the AT LED flashes.
To disengage the Pre-Tune mode, press and hold the UP and DOWN keys
until the AT LED flashes once. Release the UP and DOWN keys. Press
and hold the SCROLL key for approximately 3 seconds until the AT LED is
continuously OFF.
Note: Since the Pre-Tune mode is a single-shot operation, it will auto-
matically disengage itself once the operation is complete. If the En-
able Pre-Tune parameter in the Tune mode is enabled, then a power
interruption, the unit will first engage the Pre-Tune mode prior to en-
gaging the Auto-Tune mode when power is restored.
Also note: The Pre-Tune mode will not engage during setpoint ramp-
ing. Additionally, if the process variable is within 5% of input span
from the setpoint, or if an incorrect key sequence is used, the Pre-
Tune mode will not be engaged.
Auto-Tune Mode 3.4
The Auto-Tune mode is used to optimize tuning while the instrument is
operating.
To engage the Auto-Tune mode, with the instrument in Control mode, press
and hold the UP and DOWN keys for approximately 5 seconds (the display
will flash during this period) until the AT LED flashes once. Release the UP
and DOWN keys. Press and hold the AUTO/MAN key for approximately 3
seconds until the AT LED lights continuously.
