Siemens UL 489 Operating Instructions Manual page 183

Additional functions
The metering function Plus offers two additional functions:
- two independent waveform buffers
- harmonic analysis
The two independent waveform buffers can be used to analyze the current and voltage values at the time of the event.
If the waveform buffers are programmed to "recording" (standard setting), continuous recording takes place until a previously defined event
occurs. Then, the recording is stopped, and the current or voltage waveforms at the time of the event can be observed on a visual display
(graphical LCD, laptop or PC). The time window is one second; the resolution is 1649 values/second.
Settings for waveform buffers
Currents
Voltages
The waveform buffers can also be started or stopped individually via the communication channels (PROFIBUS DP, PROFINET IO, 
Modbus TCP, Modbus RTU, c).
The waveform buffers can be parameterized via:
- TD400 and the software "powerconfig"
- the COM modules with a PC with the software "powerconfig" installed
- the graphical display (ETU776)
I , I , I , I , I
L1 L2 L3 LN g
U , U , U
L1 L2 L3
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