The G.SP gain schedule Setpoint) is factory set at
1210°C. If tuning within 200°C above or below the
G.SP. you must adjust your G.SP value up or down to
maintain at least a 200°C span between the G.SP and
the SP.
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 be active. Set a value between the
control regions that show the greatest change to
achieve the best point of transfer.
Tuning
The two sets of PID values can be manually set or
automatically tuned. To tune automatically, you must
tune above and below the transfer point G.SP. If the
process value is below the transfer point G.SP, the cal-
culated values will automatically be inserted into the
PID1 set and if the process value is above G.SP, the
calculated values will automatically be inserted into the
PID2 set.
Autotuning
The Autotune feature automatically sets up the initial
values in the control parameters to suit new process
conditions by putting the controller into a one time,
self-tuning mode. For successful tuning to occur, it is
best to preheat your furnace to 50°C before proceeding
with the following steps.
To tune your furnace using autotuning:
1.
Load your furnace with a load similar to your
normal load and close the door.
2.
Set the setpoint temperature.
3.
Press the PAGE button until the display
reads, “Atun LiSt.”
4.
Press the SCROLL button until “tunE OFF”
is displayed.
5.
Press the UP or DOWN button to select
“on.”
29
O
PERATION
Note
The B thermocouple will not read accu-
rately below 250°C.
Note
To stop the tuning function, simultane-
ously press the PAGE and SCROLL
buttons.
