71M6545 MAXIM [Maxim Integrated Products], 71M6545 Datasheet - Page 106

• Manufacturer Part Number: 71M6545
• Description: Four-Quadrant Metering, Phase Metrology Processors Flash/RAM Size
• Manufacturer: MAXIM [Maxim Integrated Products]

Data Sheet 71M6545/H
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 control field EQU[2:0] (I/O RAM 0x2106[7:5]).
WnSUM_X is the Wh value accumulated for phase n 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 WnSUM_X is 0.135 µWh.
5.4.8.1 Instantaneous Energy Measurement Variables
InSQSUM_X and VnSQSUM are the squared current and voltage samples acquired during the last accumulation
interval. INSQSUM_X can be used for computing the neutral current.
Address
Address
The RMS values can be computed by the MPU from the squared current and voltage samples as follows:
106
Ix
0x8A
0x8B
0x8C
0x8D
0x8C
0x8D
0x87
0x88
0x89
0x8E
0x8F
0x8E
0x8F
0x90
0x91
0x92
0x90
0x91
0x92
CE
CE
RMS
=
IxSQSUM
VAR0SUM_X
VAR1SUM_X
VAR2SUM_X
VARSUM_X
V0SQSUM_X
V1SQSUM_X
V2SQSUM_X
V0SQSUM_X
V1SQSUM_X
V2SQSUM_X
I0SQSUM_X
I1SQSUM_X
I2SQSUM_X
I3SQSUM_X
I0SQSUM_X
I1SQSUM_X
I2SQSUM_X
I3SQSUM_X
W2SUM_X
Name
Name
Table 72: CE Energy Measurement Variables (with Shunts)
Table 73: CE Energy Measurement Variables (with CTs)
⋅
N
LSB
ACC
© 2008–2011 Teridian Semiconductor Corporation
The signed sum:
VAR0SUM_X+VAR1SUM_X+VAR2SUM_X.
The sum of VARh samples from each wattmeter
element.
Neutral Current:
I
⋅
3600
LSB
LSB
LSB
LSB
W
W
I
⋅
I
LSB
LSB
= 6.1903125*10
F
= 9.9045*10
= 1.0856*10
= 1.0856*10
LSB
S
LSB
I
I
= 6.3968*10
= 1.0856*10
V
V
= 1.0856*10
= 9.4045*10
Description
Description
-13
-12
-12
Vx
* IMAX
VMAX IMAX Wh.
VMAX IMAX VARh.
-14
-13
-12
RMS
* IMAX
-12
* (IMAX
* (IMAX
-13
=
2
* VMAX
*VMAX
A
2
2
VxSQSUM
h (PRE_E=0)
A
2
2
2
) A
) A
h (PRE_E=1)
2
2
V
2
2
V
h
h
2
2
h
h
⋅
N
LSB
ACC
V
⋅
Figure 27
Figure 28
3600
Configuration
Configuration
PDS_6545_009
⋅
F
S
(page 72)
(page 73)
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