24
Pb–INt
HI– LMt
SP tOO
CLOSE
INCrSE
StEP
SLO
PrCESS
NOISY
CLOSE
SP tOO
PrCESS
INPUt
Abort
USEr
LIMItS
UPdAtE
OUt
tIME
Error
A–tUNE
CAUtN
A–tUNE
FAIL
Flashing
with
or
or
Flashing
with
or
or
or
or
or
or
Message
Explanation
Action
The process is too slow for the auto tuning
to work correctly.
The input failure level has been exceeded,
possibly due to a broken sensors or the
process has exceeded one of the auto-
tune limits.
With '
At Set Point'
tuning, the ratio of
process oscillation to hysteresis value is
too small for best results.
The auto-tune process has selected a
proportional band or integral action time
above the high limits of these parameters
so the high value has been used.
Because of the process characteristics,
re-trying the auto-tuning process is
unlikely to improve the calculated
control parameters.
Restart auto-tune with a larger output
step size or a smaller hysteresis value.
Hysteresis must be at least equal to and
preferably greater than process noise.
If possible, use a larger output step
value.
Check input wiring to find the cause of
the failure or restart auto-tuning with a
smaller output step size.
The process variable signal is excessively
'noisy'.
Check input wiring to try and find the
source of the problem. If the process is
changing rapidly then allow it to settle
before re-trying the auto-tuning
process.
With '
Start-up'
tuning, the process variable
is <10% of the display range, below the
control set point.
Allow the process variable to move
further below the control set point
before re-trying '
Start-up
' auto-tuning.
Alternatively, use the '
At Set Point
' auto-
tune facility.
With '
Start-up'
tuning, although the control
set point was >10% of the display range
above the process variable, it may still be
too close to allow the auto-tune facility to
determine the process characteristics
accurately.
If desired, allow the process variable to
move further below the control set point
(by changing the control output in the
manual control mode) before re-trying
'
Start-up
' auto-tuning. Alternatively, use
the '
At Set Point
' auto-tune facility.
Operator has stopped auto-tune
process.
None.
Non-volatile memory failure while
updating control parameters.
Re-try auto-tune, if error persists
contact local Service Organization.
The auto-tune process is too slow.
If possible, use a larger output step
value. Otherwise, for '
Start-up'
auto-
tuning, move the process closer to the
set point, or, for '
At Set Point
' auto-
tuning, reduce the hysteresis value.
…5
CONTROL OPERATION
5.8
Auto-tune Diagnostic Messages
Table 5.1 Auto-tuning Error and Diagnostic Messages
Summary of Contents for C1900RC
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