4. Press several times until appears on the display.
5. Press for at least 3 seconds. The display will begin to flash and the
auto-tuning procedure will begin.
3 -11 Auto-tuning
The auto-tuning process is performed at set point.
The process will oscillate around the set point during the tuning process. Set a set point to a lower value if
overshooting beyond the normal process value set point is likely to cause damage.
The auto-tuning is applied in the following cases:
Initial setup for a new process
When set point is changed substantially from the previous auto- tuning value
When control result is unsatisfactory
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Operation:
2. Set the correct values for the setup menu of the unit. Don not use a zero value for PB and TI , otherwise, the
auto-tuning program will be disabled. The LOCK parameter should be set at NONE.
3. Set the set point to a normal operating value or a lower value if overshooting beyond the normal process value is
likely to cause damage.
NOTE :
The ramping function, if used, will be disabled once auto-tuning is initiated.
The auto-tuning mode is disabled as soon as either failure mode or manual control mode occurs.
1. The system has been installed normally.
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Procedures:
The auto-tuning can be applied either as the process is warming up (Cold Start) or as the process has been in
steady state (Warm Start).
After the auto-tuning procedure is complete, the AT indicator will cease to flash and the unit will revert to PID control
by using its new PID values. The PID values obtained are stored in the nonvolatile memory.
Auto-Tuning Error
If auto-tuning fails, an ATER message will appear on the display if:
Solutions to
1. Try auto-tuning once again.
2. Do not change the set point value during auto-tuning procedure.
3. Do not set zero value for PB and TI.
4. Use manual tuning instead of auto-tuning. (See section 3-12).
5. Touch RESET key ( or ) to reset message.
PB exceeds 9000 (9000 PU, 900.0°F or 500.0°C).
or TI exceeds 1000 seconds.
or set point is changed during auto-tuning procedure.
