50
EB 8389-1S EN
Cycle counter histogram
Short-term monitoring
To recognize short-term changes in the cycle
spans or cycle height, the positioner analyz-
es the last 100 cycle heights or cycle spans.
The positioner saves the cycle heights or cy-
cle spans in a circular buffer, which holds
100 measured values at one time.
−
'Mean time': Contains the average class
assignment for the last 100 measured
values.
Defining parameters
1.
Select classification for status messages.
1.
Device settings > Alarm settings > Status
classification > Valve
Packing leakage
−
Possibly to be expected soon: [ ], ,
,
8.1
Analysis and monitoring
The load on the bellows and/or packing can
be read from the 'Dynamic stress factor' pa
-
rameter. The value is determined from the cy-
cle spans or cycle heights and takes into ac-
count the type of packing used in the valve.
A 'Packing leakage' message is generated
with the selected status classification whenev
-
er:
−
The number of measured cycle spans ex-
ceeds 450000 when 'Live-loaded' is se
-
lected as the stem seal.
−
The number of measured cycle spans ex-
ceeds 180000 when 'Adjustable' is se
-
lected as the stem seal.
−
The number of measured cycle spans ex-
ceeds 90 % of the 'Max. cycle count'
when 'Other' is selected as the stem seal.
−
The number of measured cycle heights
exceeds 180000 when 'Bellows seal' is
selected as the stem seal.
Measured process values
−
Dynamic stress factor
Diagnostics > Monitoring > Valve
−
Packing leakage: , , ,
8.2
Resetting single status mes
-
sages
The 'Packing leakage' message is reset by
selecting and executing the command "Reset
'Cycle counter histogram
"
or "Reset 'Short-
term cycle counter histogram".
By selecting and executing the "Reset 'Cycle
counter histogram" command, all measured
data of the histogram and the short-term
monitoring as well as the 'Dynamic stress
factor' are reset.
By selecting and executing the command
"Reset 'Short-term cycle counter histogram",
the measured data in the
Short-term moni
-
toring
folder are reset.
Diagnostics > Service/maintenance > Reset
−
Reset 'Cycle counter histogram'
−
Reset 'Short-term cycle counter histogram'