Athena Technologies 16C - Manual (Page 30)

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Autotuning
To place the controller in Autotune mode:
1) Configure the controller by following the directions for
Initial Setup Sequence through Step 3 on page 7. Set
damping parameter. (See page 22.)
2) If the controller is not already in Standby mode, place it
in Standby now as follows. Press and hold the
Mode/Enter key for three seconds. Display will indicate
your current operating mode. Press the Raise key or
Lower key to select Standby. Press Mode key again
and the display will alternate between and the pro-
cess value. This will deactivate all outputs.
3) If Setpoint Value has not been entered, adjust setpoint
now by using the Raise or Lower key to set the desired
setpoint.
4) Wait for process to stabilize before proceeding, e.g., in the
case of a heating and cooling process, return to ambient
temperature.
5) Initiate Autotuning. Press and hold the Mode/Enter key
again for three seconds, then press the Raise or Lower
key repeatedly until appears. Finally, press the
Mode/Enter key again. The display will alternately indicate
and process value as the controller “learns” the
proper proportional band, derivative, and integral values
for the process. If unacceptable overshoot occurs on
restart, shut down the process and increase the damping
setting. If sluggish response is observed, shut down the
process and decrease the damping setting.
In order for the controller
to autotune properly, the
setpoint value must be at
least 1% of span above or
below the initial process
value. Make sure that
the Setpoint Target Time
parameter is set to OFF.
Tuning accuracy increas-
es as the spread between
ambient and setpoint
value increases.
Tuning should be
performed with system
in equilibrium (no latent
energy remaining).