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− delta y-monitoring value (Code 49 - A9):
0 to 100 %, [0 %]
− Activation PST tolerance band control
(Code 49 - E5): Yes, [No]
− PST tolerance band (Code 49 - E6):
0.1 to 100.0 %, [5.0 %]
Settings > Positioner > Error control >
Classification report > Extended > PST/FST
3.
− PST/FST - Status active:
, [
],
,
Diagnosis > Tests > Partial stroke test
4.
Either:
− Target PST testing mode (Code 49 - A2):
[PST Man]
− Start test
Or: (with a control valve only in manual mode
(MAN), with an on/off valve only in automat-
ic mode (AUTO))
− Target PST testing mode (Code 49 - A2) =
PST Auto, [PST Man]
− Auto test time (Code 49 - A3):
[1 h] to 2345 d
NOTICE! The positioner is write-protected
when tests are performed according to a
schedule (local operation and operating soft-
ware).
Code 0 reading: "OC" and "PST" in alternat-
ing sequence
Code 3 reading: "PST" blinks.
Note:
Cancel the test by right-clicking 'Stop
test' and selecting 'Execute' or by
pressing the rotary pushbutton at the
positioner.
After the test has been canceled, the
EB 8389S EN
positioner remains in selected mode.
The 'Status of partial stroke test'
reading indicates 'Not successful'.
In TROVIS-VIEW the test information and
progress flag of the test are displayed. The
'Test information' status indicates 'Test not
active' after the test is finished.
Note concerning setting the PST diagnostic
parameters
− We recommend only to start the partial
stroke test when the valve is in the end
position. In on/off valves, the start value
must be the same as the operating point.
− The 'Ramp time (rising)' must be greater
than the corresponding value for 'Mini-
mum transit time close' (Code 41) deter-
mined during initialization.
− The 'Ramp time (falling)' must be greater
than the corresponding value for 'Mini-
mum transit time open' (Code 40) deter-
mined during initialization.
Tip:
Users with expert knowledge of valve
diagnostics can determine appropri-
ate ramp times by performing a full
stroke test. See
− The 'Scan rate' must not be lower than
the indicated 'Min. recommended scan
rate'. The 'Min. recommended scan rate'
is calculated from the 'Duration of the
test'.
Tests
Section 7.4.
u
69
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