31
Flashes
Autotuning
If a tune error condition occurs, the upper display will toggle
between
and a numeric error code for three seconds
before the tune process terminates. The controller will then
automatically go into Standby mode when a tuning error
occurs. Possible error codes are:
02 = No PID Device Configured
03 = Incorrect Output Action
05 = Insufficient Setpoint-Process Value Deviation
08 = Invalid Tune Results
09 = Tune Timeout
Autotuning Procedure Diagram
Note: Keep in mind that the setpoint value must be at least
1% of span above or below the initial setpoint, and that the
process value must be stable prior to initiating the tune.
Hold for
three
seconds
Press
Press
Once
Current
Mode
Standby
Mode
Flashes
Hold for
three
seconds
Press until
appears
Press
Once
Controller is
now autotuning
Standby
Mode
Autotune
Mode
30
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 16. Set
damping parameter. (See page 26.)
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 process 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 increases
as the spread between
ambient and setpoint
value increases.
Tuning should be
performed with system
in equilibrium (no latent
energy remaining).
