23
…5.7.1 Auto-tuning Page
Auto-tune Status/Enable
Select
StArt to enable auto-tune cycle. The 'AT' (auto-tune) l.e.d. is
illuminated. The time taken for completion of auto-tuning is dependent on the
speed of response of the controlled process.
✶
Note. If Auto-tune is selected it is not possible to exit the Auto-tuning Page
until the auto-tune cycle is complete or ended by the operator.
Process Variable (upper display)
Control Set Point Value (lower display)
The set point is displayed for monitoring only and cannot be changed at this
frame.
Process Variable (upper display)
Control Output (lower display)
The output value is displayed for monitoring only and cannot be changed at this
frame.
Auto-tune Status and Enable/Disable
At–ON – (Auto-tune On) auto-tuning can be switched off by
pressing the
switch
to select
StOP and then pressing the switch.
At–UPd – (Auto-tune Update) the auto-tune cycle is complete and
the calculated terms are being written to memory.
At–ENd – (Auto-tune End) the auto-tune cycle is complete. If no
failures occur during the cycle, the calculated values are
loaded into memory as new control terms and the
instrument returns automatically to the
Operating Page. If
failures or cautions occur during auto-tuning, error
messages are displayed in the next frame.
Auto-tune Error Messages
If a
Failure occurs the controller reverts to the manual control mode, the old
control terms are retained and the auto-tune l.e.d. flashes.
If a
Caution occurs the calculated control terms are loaded into memory and
control continues in the automatic mode. Any errors are acknowledged when
exiting this frame and the auto-tune l.e.d. flashes.
For an explanation of error messages – refer to Table 5.1 overleaf.
At–ON
At–UPd
At–ENd
A-tUNE
FAIL
StArt
At–OFF
AUtO
tUNE
100.3
110.5
AL
RMT
AT
MAN
Constant L.E.D.
100.3
100.5
100.3
OP 50.0
100.3
W 50.0
or
StArt
or
or
A–tUNE
CAUtN
A–tUNE
or
StOP
Flashing With Flashing With
Error
Message
Error
Message
AUtO
tUNE
Control Output Valve
Status/Position
Errors
100.3
100.5
Operating
Page
No
Errors
5 CONTROL OPERATION…
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