Datasheet
71M6541D/F/G and 71M6542F/G Data Sheet
132 Rev 4
WSUM_X (CE RAM 0x84) and VARSUM_X (CE RAM 0x88) are the signed sum of Phase-A and Phase-B Wh
or VARh values according to the metering equation specified in the I/O RAM control field EQU[2:0] (I/O
RAM 0x2106[7:5]). WxSUM_X (x = 0 or 1, CE RAM 0x85 and 0x86) is the Wh value accumulated for phase x
in the last accumulation interval and can be computed based on the specified LSB value.
5.3.8.2 Instantaneous Energy Measurement Variables
IxSQSUM_X and VxSQSUM (see Table 87) are the sum of the squared current and voltage samples
acquired during the last accumulation interval.
Table 87: CE Energy Measurement Variables (with Local Sensors)
CE
Address
Name Description
Configuration
0x8C
I0SQSUM_X
The sum of squared current samples from each
element.
LSB = 9.4045*10
-13
IMAX
2
A
2
h
For ce41a04, LSB = 6.6952*10
-13
IMAX
2
A
2
h.
When EQU = 1, I0SQSUM_X is based on IA and
IB.
Figure 35 (page 93)
Figure 37 (page 95)
0x8D
I1SQSUM_X
0x90
V0SQSUM_X
The sum of squared voltage samples from each
element.
LSB = 9.4045*10
-13
VMAX
2
V
2
h
For ce41a04, LSB = 6.6952*10^
-13
VMAX
2
V
2
h.
0x91
†
V1SQSUM_X
†
71M6542 only.
Table 88: CE Energy Measurement Variables (with Remote Sensor)
CE
Address
Name Description Configuration
0x8C
I0SQSUM_X
The sum of squared current samples from each
element.
LSB
I
= 2.55872*10
-12
* IMAX
2
A
2
h
When EQU = 1, I0SQSUM_X is based on IA and
IB.
Figure 36 (page 94)
Figure 38 (page 96)
0x8D
I1SQSUM_X
0x90
V0SQSUM_X
The sum of squared voltage samples from each
element.
LSB
V
= 9.40448*10
-13
* VMAX
2
V
2
h
0x91
†
V1SQSUM_X
†
71M6542 only.
The RMS values can be computed by the MPU from the squared current and voltage samples as follows:
Note: N
ACC
= SUM_SAMPS[12:0] (CE RAM 0x23).
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 89.
MAINEDGE_X (CE RAM 0x83) reflects the number of half-cycles accounted for in the last accumulated
interval for the AC signal of the phase specified in the FREQSEL[1:0] field in CECONFIG (CE RAM 0x20[7:6]).
MAINEDGE_X is useful for implementing a real-time clock based on the input AC signal.
ACC
SI
RMS
N
FLSB
IxSQSUM
Ix
⋅⋅⋅
=
3600
ACC
SV
RMS
N
FLSBVxSQSUM
Vx
⋅⋅⋅
=
3600