Samson 373 Series - Drive Signal Diagram Hysteresis (D2)

Viewing the recorded parameters:
The
Drive signal diagram steady-state folder
contains the reference and repeated mea
-
surements plotted in a graph.
The individual measured points are saved in
the corresponding subfolders:
> Reference valve position
> Reference drive signal
> Repetition value of valve position
> Repetition value of drive signal.
Test requirements:
4
A successfully plotted reference graph
and repetition lines are necessary in or
-
der to analyze the data.
If a reference graph still has not been
plotted on starting the test, this test is
adopted as the reference.
4
Refer to section 1.6 in case a double-act-
ing actuator with reversing amplifier or a
booster is used or SUb initialization
mode is set.
3.2 Drive signal diagram
hysteresis (d2)
Similar to the corresponding test in auto
-
matic mode, this test (
tESt d2 ) is used to an
-
alyze the change in friction forces.
However, unlike the test in automatic mode,
this test causes the valve to move to defined
valve positions over the full range of the
valve, and determines
∆
y for each valve po
-
sition.
The valve is made to move to fixed nodes of
the valve position x and the valve position is
ramped up (< 1 %) correspondingly.
The drive signal y and the change in valve
opening are analyzed during this test phase
concerning changes in
∆
y for changes in di-
rection, to precisely check the results or
alarms issued in automatic mode.
To enable a test, the tolerance band (Code
19 or in
Positioner folder (> Error control )
must be greater than 1 % (default: 5 %).
If the valve cannot move to a certain valve
position node or the setpoint leaves the tol-
erance band during the test, an alarm is
generated in
Test information and the test is
canceled.
The necessary data set for the reference
graph is automatically plotted and stored di
-
rectly after initialization. The start time for
the reference graph is stored with a refer
-
ence time stamp in the non-volatile memory
of the positioner.
Any further measurement is stored as a re
-
peated measurement. Previously recorded
repeated measurements stored in the
positioner are overwritten. However, you
can upload previous repeated measure
-
ments to a PC before you start a new test.
EB 8388 EN 23
Tests MAN