EB 8389-1S EN
67
Course of end position
10
Course of end position
The course of end position is used to detect
an alternating zero point or a creeping zero
point shift due to seat and plug wear or dirt
between the seat and plug.
Data are recorded in the background re-
gardless of the operating mode selected if
the tight-closing function (Code 14) is active.
Data logging does not need to be activated.
The course of the end position records the
valve position x and the signal pressure p
out
together with the time stamp by the operat-
ing hours counter when the valve moves to
the lower end position. The new recorded
valve position is compared to the last saved
zero point. If it differs by the 'Recording
threshold' from the last value, the data of the
new zero point are saved.
A graph of the recorded valve positions at
the lower end position is plotted over time.
The positioner saves the valve positions in a
circular buffer, which holds 30 measured
values at one time. The recorded measured
data are listed in the
Lower end position
folder.
Defining parameters
1. Activate tight-closing function.
2.
Define 'Recording threshold'.
3.
Select classification for status messages.
Fig. 15:
Diagnostics > Monitoring/tests >
Course of end position
