Watlow Series F4S/D - Manual (Page 71)

Wa t l o w S e r i e s F 4 S / D F e a t u r e s ■ 6 . 7
Other Features
Autotuning
The autotuning feature allows the controller to
measure the system response to determine effective
settings for PID control. When autotuning is initi-
ated the controller reverts to on-off control. The
temperature must cross the auto-tune set point
four times to complete the autotuning process.
Once complete, the controller controls at the nor-
mal set point, using the new parameters. The F4
stores the value in the PID set specified.
Location in software: Operations Page > Autotune
PID > Channel 1 Autotune > PID Set x (1 to 5) or
Channel 2 Autotune > PID Set x (6 to 10).
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CAUTION: Choose an auto-tune set point value that will
protect your product from possible damage from overshoot
or undershoot during the autotuning oscillations. If the
product is sensitive, carefully select the auto-tune set
point to prevent product damage.
Figure 6.7 — Autotuning.
✔ NOTE:
For manual tuning, see the Operations Chapter.
Time
Temperature
Auto-tune begins
(on-off control). Process Set Point
Auto-tune Set Point
(Default is 90% of process set point.)
Auto-tune is complete
(PID control).
Power-Out Time/Power-Out Action
The Power-Out Time and Power-Out Action param-
eters direct the F4’s response to the interruption of
electrical power while running a profile. The F4’ s
battery-powered real-time clock tracks the amount
of time the power is out. When power is restored,
the controller compares this amount of time to the
Power-Out Time setting and takes whatever action
is selected in the Power-Out Action setting.
First, determine how long the power can be inter-
rupted without adversely affecting results. Set the
Power-Out Time to this time. If power is returned
in less time than this setting, the profile will re-
sume running. (The profile run time stops while
the power is off.) If power is returned after a time
longer than this setting, the F4 will take action
based on the user-configured Power-Out Action pa-
rameter: Continue (resume the profile at the point
that power was interrupted); Hold (hold the profile
at the point that power was interrupted); Termi-
nate
(stop the profile using the End step condi-
tions); Reset (restart the profile from Step 1); Idle
(stop the profile and transfer to an idle setpoint).
Location in software: Setup Page > System > Pow-
er-Out Time > Power-Out Action.
✔ NOTE:
The Power Out Action occurs only if a profile was run-
ning when the power went out. If a profile was on hold, it
will return to its Hold status when the power returns.