7
Control mode operation
Manual operation provides direct (time proportioned % time) control from -100% to 100%. A negative value is
allowed only when Ot 1=Cool. Automatic operation provides sensory feedback ON/OFF or PID control. When
the operation transfers from automatic to manual operation, the power level from automatic operation is retained
and restored to the previous set point.
The % LED indicates manual operation. The LED is on when in Manual operation and off when in AUTO
operation. When the LED is flashing, press the
Infinity
key again within 5 seconds to complete the change in
operation. It the sensor is open and LOC=0, 1 or 2, the control switches to Manual operation if the output was
stable before the break occurred.
Tuning-Automatic
It is recommended that auto-tuning be used each time a new process is initiated. If the process is being
duplicated, the parameters learned in the initial auto tune setup are stored in the memory of the control and the
auto-
tune procedure isn’t required in most applications.
Auto-tuning: This control can automatically tune the PID parameters to fit the characteristics of your particular
thermal system.
Auto-tune can only be used when Output 1 setting is hEAt and heat algorithm (h.Ag, page 5) is set for PID mode.
The heat algorithm setting is set for PID from the factory. When the auto-tune sequence has started, the lower
display will flash between tun1-attn and the main operation screen.
Changing the set point, while in auto-tune mode, will not change the set point value. The displayed value will
change but the control has locked in the original set point value tell the auto tune in complete or has been turned
off by the user. Once the control has finished "learning" the system, it returns to standard PID control with the
values automatically set. Auto-tuning is complete within 80 minutes. In order for the control to successfully
complete auto-tune, the process must cross the 90% set point value four times within 80 minutes after auto-tune
has started. If this does not happen within the 80 minute time limit, Pb1 remains at 0 and the control will operate
with the factory default PID values.
