Datasheet

FDS_6533_6534_004 71M6533/G/H and 71M6534/H Data Sheet
Rev 2 101
WSUM_X and VARSUM_X are the signed sum of Phase-A, Phase-B and Phase-C Wh or VARh values
according to the metering equation specified in the I/O RAM register EQU[2:0]. WxSUM_X is the Wh value
accumulated for phase x in the last accumulation interval and can be computed based on the specified
LSB value.
For example, with VMAX = 600 V and IMAX = 208 A, the LSB for WxSUM_X is 0.1173 µWh.
Instantaneous Energy Measurement Variables
Table 61 contains various measurement variables. IxSQSUM_X and VxSQSUM are the squared current and
voltage samples acquired during the last accumulation interval. They can be used to calculate RMS voltages
and currents. INSQSUM_X can be used for computing the neutral current.
Table 61: CE Energy Measurement Variables
CE
Address
Name Description
0x8F
I0SQSUM_X
The sum of squared current samples from each element.
LSB
I
= 9.4045*10
-13
IMAX
2
/ In_8
2
A
2
h
0x90
I1SQSUM_X
0x91
I2SQSUM_X
0x92
INSQSUM_X
The sum of squared current samples from the calculated neutral:
∑
++
2
210
)( III
LSB=9.4045*10
-13
IMAX
2
/ In_8
2
A
2
h
0x99
I0SQRES_X
Residual current measurements with double-precision accuracy. The
exact current is:
ISQn = InSQSUM_X + InSQRES_X
0x9A
I1SQRES_X
0x9B
I2SQRES_X
0x9C
INSQRES_X
0x93
V0SQSUM_X
The sum of squared voltage samples from each element.
LSB
V
= 9.4045*10
-13
VMAX
2
V
2
h
0x94
V1SQSUM_X
0x95
V2SQSUM_X
The RMS values can be computed by the MPU from the squared current and voltage samples as follows:
Other Transfer variables include those available for frequency and phase measurement, and those reflecting
the count of the zero-crossings of the mains voltage and the battery voltage. These transfer variables are
listed in Table 62.
MAINEDGE_X reflects the number of half-cycles accounted for in the last accumulated interval for the AC
signal of the phase specified in the FREQSEL1 and FREQSEL0 registers. MAINEDGE_X is useful for
implementing a real-time clock based on the input AC signal.
ACC
SI
RMS
N
FLSBIxSQSUM
Ix
⋅⋅⋅
=
3600
ACC
SV
RMS
N
FLSBVxSQSUM
Vx
⋅⋅⋅
=
3600