EB 8389-1S EN
49
Cycle counter histogram
8
Cycle counter histogram
The cycle counter histogram provides a statis-
tical analysis of the cycles. As a result, the
cycle counter also provides information on
the dynamic stress of a bellows seal and/or
packing.
Data are recorded automatically 15 minutes
after initialization (regardless of the operat-
ing mode selected). Data logging does not
need to be activated.
The positioner records the number of cycle
spans when the stem seal setting is set to
'Live-loaded', 'Adjustable', 'Other' or '-/-'.
A valve cycle span starts at the point where
the valve stroke changes direction until the
point where it changes direction again. The
valve stroke between these two changes in
direction is the cycle span.
The positioner records the cycle height when
the 'Stem seal’ setting is set to 'Bellows seal'.
The cycle height is the travel performed be-
tween two changes in direction.
The cycle spans or cycle heights are as-
signed to classes. The distribution showing
how often the cycle span or height occurred
within a class is shown in a bar graph.
−
'Mean value': Average class assignment
of cycle height calculated from the 'No.
of cycles'
−
'No. of cycles'
The measured data are saved every 24
hours in the positioner.
Defining parameters
1. Select the type of stem seal.
(*When 'Other' is selected as the stem
seal, the additional parameter 'Max. cy
-
cle count' must also be set).
1.
Device settings > Alarm settings
−
Stem seal: [-/-], Live-loaded, Adjustable,
Bellows seal, Other
*
−
Max. cycle count:
1 to 1000000000, [1000000]
Fig. 9:
Diagnostics > Monitoring/tests > Histograms >
Cycle counter histogram
