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8 Configuring the Recorder
D03283R01.10 TESLA LITE User Manual 8-21
8.8 Summation Channel
Description
Summation Channels combine up to three analog inputs to create a summed
channel. Each input can be scaled and rotated before it is summed. Previously
combined summation channels can be used as an input to a new summation
channel.
Input
Analog Input Channels or other Summation Channels can be used as inputs to
a Summation Channel. The summation can have two or three inputs. If a Sum-
mation Channel is used as an input, it must have a lower
Summation Index.
Calculation
Each input is converted to a phasor using a DFT function and is scaled and ro-
tated using the
Scale Factor and Angle Offset settings.The resulting phasors are
added to form the summation.
The high speed recording of a Summation Channel is created by adding the in-
dividual data points from the input channels. The
Scale Factor is applied to
each channel before the addition.
Triggers
• High & low magnitude
• Negative and positive rate of change
To prevent multiple triggers on threshold conditions, an hysteresis of 2% of
setting is applied to magnitude triggers.
Recording
High Speed : generates a channel that is the sum of the individual data samples
with the Scale Factor applied. A high speed channel is not generated if a non-
zero Angle Offset has been specified on any of the summation’s input channels.
Low Speed : generates a channel that is phasor sum of the input channels at a
rate of one phasor per cycle.
Number of
Channels
10 Summation Channels are available.
Types
Specific: Va, Vb, Vc, Ia, Ib, Ic, In (use where appropriate)
Generic: Vac, Iac
Note: Summation Channels are handled as phasor sums for trigger-
ing, metering, low speed recording and trending. Both the
Scale Fac-
tor and Angle Offset settings are applied for these uses.
For high speed recording, Summation Channels are displayed as a
the
sum of the individual data samples with only the Scale Factor set-
ting applied. High speed Summation channels are not recorded if a
non-zero
Angle Offset has been specified.