Tuning - Barnstead F62730 Operation Manual

Note
Display will flash "tu.ER" if an error
occurs during tuning. To clear the
error and restart tuning, simultaneous-
ly press the PAGE and SCROLL but-
tons and follow the steps outlined in
"Autotuning."
Note
To stop the tuning function, simultane-
ously press the PAGE and SCROLL
buttons.
8 S
EGMENT

Tuning

The purpose of tuning your furnace is to match the char-
acteristics of your controller to the characteristics of the
process being controlled. Good control is evidenced by:
stable, straight-line control of the setpoint temperature
with no fluctuations; No overshoot or undershoot of the
setpoint temperature; rapid restoration of the setpoint
temperature when external disturbances cause deviations
from the setpoint.
This controller has automatic tuning features which install
optimum tuning parameters to give the best temperature
accuracy. No manual loading of tuning parameters is
needed. We recommend that you tune the furnace to your
specific application to obtain the best results. To provide
the best temperature accuracy possible, use these fea-
tures when you install your furnace and whenever you
change your application or procedure.
Tuning Error
The display will flash "tu.ER" if an error occurs during tun-
ing. To clear the error and restart tuning, simultaneously
press the PAGE and SCROLL buttons and follow the
steps outlined in "Autotuning."
G.SP: Gain Scheduling
Gain scheduling is the automatic transfer of control
between two sets of PID values. The controller does this
at a presettable process value. Gain scheduling is used
for difficult control processes which show large changes
in their response time or sensitivity at high or low temper-
atures, or when heating or cooling.
The G.SP gain schedule setpoint is factory set at 700° C.
The G.SP must be adjusted to 200°C from the desired
setpoint temperature when tuning.
Setting the Transfer Point
If gain scheduling has been enabled, "G.SP will appear at
the top of the PID list. This sets the value at which the
transfer will occur. When the process value is below this
level, PID1 will be active and when it is above, Pid2 will
P M
ROGRAMMABLE ODEL W
/OTP
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