Samson 3730 Series Mounting And Operating Instructions page 10

ESD functions
Cancellation conditions
To ensure that the running process is not dis-
rupted and that the shut-off valve does not
slam shut unintentionally, it is advisable to
define conditions that cause the positioner to
cancel an active partial stroke test. The
positioner issues an alarm when a test has
been cancelled (see section 2.2).
Possible cancellation conditions are:
4
Max. test duration : The test is cancelled
when the maximum permissible test du-
ration (range: 30.0 to 3000.0 s) is ex-
ceeded.
4
x control value : The test is cancelled
when the adjusted valve position (range:
–10 to 110 %) is exceeded.
The condition is only active when Activa-
tion x control is set to "On".
4
y control value : The test is cancelled
when the adjusted drive signal (range: 0
to 9999 1/s) is exceeded. The Minimum
value y control (in TROVIS-VIEW 3 un-
der Display) can be used a guide value
for monitoring. The smallest drive signal
value determined during the last partial
stroke test is given under this parameter.
The condition is only active when Activa-
tion y control is set to "On".
Monitoring the drive signal y only makes
10
EB 8388-1 EN
sense when the partial stroke test is per-
formed as a ramp function because the
y cancellation condition is always met
with the step change function.
4
ESD tolerance band : The test is cancelled
when the deviation of the valve position
exceeds the adjusted value (range: 0.1
to 100.0 %).
The condition is only active when Activa-
tion tolerance band control is set to
"On".
During the course of the test, the following
parameters are changed as specified:
4
Lower x-range value (code 8): 0 %
4
Upper x-range value (code 9): 100 %
4
Lower/upper x-limit (codes 14/15): OFF
4
Pressure limit (code 16): active pressure
limit increased by one stage
4
Characteristic (code 20): linear
4
w-ramp OPEN/CLOSED (codes 21/22):
variable
The data can be reset in the [Status mes-
sages] folder under Reset.