Waveform Data Storage Format; Types Of Waveform Data; Key Terms - Siemens US2:9810T24V User Manual

Logging
Waveform information is used to help identify power system disturbances, which are an
increasing concern for industrial plants, hospitals, data centers and other facilities where the
equipment is sensitive to voltage or current sags, swells, transients, and momentary interruptions.
Waveform information is also used to help ensure compliance with power quality standards.
In addition to measuring and recording numerical values for voltage and current, your meter can
also capture the sinusoidal waveform data. The current and voltage waveform data provides
additional information for analysis of the system's power quality or a power quality event.
When your system's nominal parameters are programmed into the meter, power quality events
such as sags, swells and transients are automatically detected and voltage and current waveform
data is logged. The default factory settings for sag/swell and transient detection are sufficient for
most applications, but you can also modify the amount of deviation from the nominal required to
trigger waveform recording.

Waveform data storage format

Your meter's waveform data storage format is defined by:
• Cycles: the number of cycles included in the waveform (its duration).
• Samples: samples per cycle, which is the number of waveform data points collected in each
cycle.
This gives you the option to record a lot of information for a very short duration or less information
over a longer duration. You can also configure the waveform recording to record pre-event and
post-event data.

Types of waveform data

You can use your meter to detect ITI (CBEMA) - type disturbances, and determine information
regarding the magnitude and duration of each disturbance. This information can be used by your
energy management system to plot the disturbance on an ITI (CBEMA) curve.
COMTRADE waveform data is available from your meter.
NOTE: If you are generating COMTRADE waveform information, the associated waveform
recorders cannot be modified unless COMTRADE is disabled. If the waveform recorders are not
configured identically, COMTRADE waveform information will not be generated.

Key terms

Term
COMTRADE
ITI (CBEMA)
Nominal
227
Definition
COMmon format for TRAnsient Data Exchange (COMTRADE) is
a common format for waveform data.
A curve that graphically describes an AC input voltage envelope
which can be typically tolerated by information technology
equipment. Meter waveform information is plotted on this curve to
help evaluate power quality.
The normal or usual parameter value. For example, the nominal
voltage for many power systems is 120 V.
9810 series - User manual
7EN05-0390-08