logger
parameter and select
Execute
.
The triggering event starts data logging
when the start value exceeds or falls below
an entered value.
Enter the required value at which data log-
ging should be triggered in relation to the
setpoint in the
Start value
parameter.
Select whether data logging should start
when the entered value exceeds or falls be-
low the start value in the
Logging limit
pa-
rameter.
After being triggered, the variables w, x, y
and e are logged at the adjusted scan rate
and saved in the FIFO memory.
Additionally, there is a pretrigger time avail-
able to allow the variables to be stored that
were logged before the triggered event.
Enter the required pretrigger time by
right-clicking the parameter and selecting
Modify
. However, the pretrigger time en-
tered may not be higher than the maximum
pretrigger time determined by the
positioner. This maximum pretrigger time is
shown in the
Max. pretrigger time
parame-
ter. The data logging finishes automatically
as soon as the maximum memory capacity
of 100 measured data points for each vari-
able including the pretrigger time is
reached.
Solenoid valve condition (forced venting)
Select
Trigger status
parameter and select
Start via solenoid valve condition (forced
venting)
. Activate data logging by selecting
Start data logger
parameter and select
Exe-
cute
to start data logging as soon as the in-
tegrated solenoid valve is triggered or the
forced venting function is activated.
Similar to the travel condition (setpoint), the
variables w, x, e and y are logged at the
adjusted scan rate and saved in the FIFO
memory on triggering.
Additionally, there is a pretrigger time avail-
able to allow the variables to be stored that
were logged before the triggered event.
Enter the required pretrigger time by
right-clicking the parameter and selecting
Modify
. However, the pretrigger time en-
tered may not be higher than the maximum
pretrigger time determined by the
positioner. The data logging finishes auto-
matically as soon as the maximum memory
capacity of 100 measured data points for
each variable including the pretrigger time
is reached.
Travel (setpoint) or solenoid valve condition
(forced venting)
Select
Trigger status
parameter and select
Start via travel (setpoint)/solenoid valve
condition (forced venting)
. Activate data
logging by selecting
Start data logger
pa-
rameter and select
Execute
. The triggering
event starts data logging when the valve
travel (setpoint)/solenoid valve conditions
(forced venting) are met.
The measured data are plotted over time in
graphs. In addition, the compiled measured
data are stored in the
Measured values
folder (see Fig. 3).
2.2
Travel histogram
The valve travel histogram is a statistical
analysis of the plotted valve travel.
The histogram provides information, for ex-
ample, about where the valve mainly works
during its service life and whether it shows a
recent trend concerning changes in its work-
ing range.
The valve travel is recorded and assigned to
valve travel classes. The distribution showing
EB 8388 EN
11
Statistical information AUTO
