Operate
6.2 Parameter description
SITRANS VP300 with or without HART
Operating Instructions, 03/2011, A5E01258666-03
101
Purpose:
Specifying how the positioner is to respond if a partial stroke test
fails. A partial stroke test fails if the thresholdset in the "3.5.4.4
Threshold stroke time" (Page 103) parameter is exceeded.
Description:
No reaction: If an error occurs, the positioner returns to normal
operation. If a control deviation is not detected there, the
pressure level in the chamber reached during the test is
retained.
Aerate actuator: In the event of a fault, the drive is ventilated for
twice the positioning time. Position time: See menu "3.3
Initialization values" (Page 92)
Deaerate actuator: In the event of a fault, the drive is deaerated
for twice the positioning time. Position time: See menu "3.3
Initialization values" (Page 92)
Activate tight closing: The tight closing function is set to "Up and
down" in the event of a fault independent of the previous setting
in the "Tight closing" parameter.
"3.5.2.9 DO 1 Pulse length"
Requirements:
Alarm unit is installed.
Factory setting:
2
Setting options:
1 s
2 s
5 s
Purpose:
To output message dynamically.
Description:
SIL function
The pulse length of digital output DO 1 can be alternatively set using
the "2.2.6 DO 1 Pulse length" (Page 80) parameter.
"3.5.3 Initiate reference stroke"
Requirements:
Basic settings for partial stroke test have been made in "3.5.2 PST
A reference stroke is only informative if the control valve is in a fault-
free condition.
Setting option:
Start
Purpose:
Determination of comparison values of breakaway time, stroke time,
and total time. The reference stroke is thus the basis for setting the
associated thresholds, which can be set in the "3.5.4 PST Reference"
(Page 102) menu. If the thresholds are exceeded, a failure reaction is
triggered. How the positioner is to react is set in the "3.5.2.8 Failure
reaction" (Page 100) parameter.
