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