38
EB 8389-1S EN
On/off valve
The PST diagnostic parameter 'Lower range
value' must be within the defined position ±
'Tolerance limit' for the partial stroke test to
start.
After the partial stroke test is completed, the
valve moves back to its last position (fail-safe
position or operating point).
Canceling the partial stroke test (PST)
The partial stroke test is canceled whenever
the set point ( ) leaves the range between
'Fail-safe action limit' and 'Operating point
limit', falling below 'Operating point limit'.
After the partial stroke test is canceled, the
valve moves back to its last position (fail-safe
position or operating point).
Defining parameters
Note:
The parameters can only be defined in
TROVIS-VIEW 4 after the 'Type of ap
-
plication' has been set to 'On/off
valve'.
1. Select the type of application.
2.
Define parameters for on/off valve.
3.
Define parameters for partial stroke test
(PST). See
u
1.
Start-up
−
Type of application (Code 49 - h0):
On/off
valve
2.
Device settings > Positioner > Transfer
characteristic on/off
−
Operating point (Code 49 - h1): 0.0 to
100 %, [100 %]
−
Fail-safe action limit (Code 49 - h2): 0.0 to
20.0 %, [12.5 %]
−
Operating point limit (Code 49 - h5):
55.0 to 100.0 %, [75.0 %]
3.
Diagnostics > Monitoring/tests > Dynamic
tests > Partial stroke test (PST)
See
5.1
Diagnostics for on/off
valve
The diagnostics for on/off valve provide
statements on the valve end positions, transit
times (increasing/decreasing) and break-
away times (increasing/decreasing).
The data are recorded automatically for the
diagnostics for on/off valve in automatic
mode. Data logging does not need to be ac-
tivated.
The positioner compares the current break-
away time, transit time and valve position
with the values recorded during the reference
measurement (first analysis) while the plant is
running.
Defining parameters
Note:
The parameters can only be defined in
TROVIS-VIEW 4 after the 'Type of ap
-
plication' has been set to 'On/off
valve'.
1. Enter limits for monitoring. See
u
2.
Select classification for status messages.