Gradient Trigger (±Dm/Dt); Binary Trigger - Siemens SIMEAS R-PMU Manual

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7.2 Fault Recorders
7.2.1.2.1.2 Gradient Trigger (±dM/dt)
The gradient of a signal is the level change per time. For the TAR the trigger condition for alter-
nating signals is met, when the difference of two half cycle rms values is higher than the param-
eterized threshold for a distance of two periods. For DDAUs, the arithmetic means are compared
for a distance of two periods. A distinction is made between rising gradients (+dM/dt, i. e. positive
difference) and falling gradients (-dM/dt, i. e. negative difference).
They can be parameterized for all analog signals from tables 7-11 and 7-12 (not for symmetrical
components).
7.2.1.2.2

Binary Trigger

Status changes of the binary DAU inputs can be defined as trigger conditions. Thus, a record
can be started if a sensor changes to or leaves from the alarm state or for each state change.
The correspondence between physical and logical state change depends on the sensor type
(see table 7-14 and chapter 12.11.1).
Table 7-14
Sensor
Make contact
Break contact
For the definition of high and low levels, refer to chapter 16.1.4.
Retrigger blocking for binary signals
The retrigger blocking can be activated separately for every binary input. It is used to suppress
repeated recordings in the event of fast successive binary signal changes while recording. The
corresponding binary trigger is disabled for the preset retrigger blocking time. If the same binary
input is retriggered within the retrigger blocking time, the retrigger blocking will be restarted for
this input. All other active channels can retrigger the TAR and thus extend the fault record.
Note
The retrigger blocking time can be defined longer than the recording time. In case of a wrong
configuration, this may unintentionally avoid recordings.
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Sensor types
Logical
state change
Change to alarm state
Change from alarm state
Change to alarm state
Change from alarm state
Physical
state change
Low → High
High → Low
High → Low
Low → High
Digital Fault Recorder, SIMEAS R-PMU, Manual
E50417-H1076-C360-A5, Release 10.2012