Omega Engineering CN9400 specifications Autotune, A u t o t u n e, Tune Program, Cycle-Time

Select the most appropriate method of Autotune , Tune or Tune at Setpoint, to suit the application.

Note: The proportional cycle-time can be pre-selected before starting Autotune, see PROPORTIONAL

CYCLE-TIME.

The TUNE program should be run with the load cool. The output is cycled at 75% of the setpoint value to avoid any overshoot during the tuning cycle. The warm-up characteristics are monitored and set DAC which minimises overshoot on subsequent warm-ups.

The TUNE AT SETPOINT program is recommended:

when the setpoint is below 100°C/200°F, where TUNE’s tuning cycle at 75% setpoint may be too close to ambient to produce good results;

when the process is already hot and the cooling rate is slow;

when controlling multi-zone or heat-cool applications;

to re-tune if the setpoint is changed substantially from previous Autotune.

Note: dAC is not re-tuned by TUNE AT SETPOINT.

AUTOTUNE

TUNE PROGRAM

Temp
Setpoint
Tuning	DAC	PID
TUNE
Cycle
75% SP	11/4 on/off tuning		New PID
		cycles	values
			entered
Start TUNE
			Time
			(100% output)

Enter program mode

and from the display	TUNE
	OFF
press and hold ✱ and press ▲ once,
the controller will now display	TUNE
	ON
Exit program mode.
The TUNE program will now start. The upper display will
alternate between tune and the process temperature as it
climbs to setpoint.	TUNE
The lower display will read the setpoint value e.g.
	232
Note: During tuning, the main setpoint (SP1) LED will flash.

A u t o t u n e

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