Autotuning - Thermo Scientific 3490M Manual

Setting the Transfer Point

Autotuning

Thermo Scientific
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 calculated
values will automatically be inserted into the (SEt 1) set and if the process
value is above G.SP, the calculated values will automatically be inserted
into the (SEt 2).
The Autotune feature automatically sets up the PID values in the control
parameters to suit new process conditions. To tune your oven using
autotuning:
1. Load your oven 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."
6. Simultaneously press the PAGE and SCROLL buttons to return to the
HOME DISPLAY. The display will flash "tunE" while tuning is in
progress.
Section 6
Programmable Models
Clean Room Oven 6-15