71M6513/71M6513H
3-Phase Energy Meter IC
A Maxim Integrated Products Brand
DATA SHEET
SEPTEMBER 2011
CE Front End Data (Raw Data)
Access to the raw data provided by the AFE is possible by reading addresses 0 through 7, as listed below.
Address (HEX)
Name
Description
0x00
0x01
0x02
0x03
0x04
0x05
0x06
IA
VA
IB
VB
IC
Phase A current
Phase A voltage
Phase B current
Phase B voltage
Phase C current
Phase C voltage
Temperature
VC
TEMP
V3 monitor/comparator
input
0x07
V3
CE Status Word
Since the CE_BUSY interrupt occurs at 2520.6Hz, it is desirable to minimize the computation required in the interrupt handler
of the MPU. The CE status word can be read by the MPU at every CE_BUSY interrupt.
CE
Address
Name
Description
0x51
CESTATUS
See description of CE status word below
The CE Status Word is useful for generating early warnings to the MPU. It contains sag warnings for phase A, B, and C, as
well as F0, the derived clock operating at the fundamental input frequency. CESTATUS provides information about the status of
voltage and input AC signal frequency, which are useful for generating an early power fail warning to initiate necessary data
storage. CESTATUS represents the status flags for the preceding CE code pass (CE_BUSY interrupt).
Note: The CE does not store sag alarms from one code pass to the next. CESTATUS is refreshed at every CE_BUSY
interrupt and remains valid for up to 100µs after the CE_BUSY interrupt occurs. Unsynchronized read operations of
CESTATUS will yield unreliable results.
The significance of the bits in CESTATUS is shown in the table below:
CESTATUS Bit
Name
Description
31-29
28
Not Used These unused bits will always be zero.
F0
F0 is a square wave at the exact fundamental input frequency.
Normally zero. Becomes one when |VC| remains below SAG_THR for SAG_CNT
samples. Will not return to zero until |VC| rises above SAG_THR.
27
26
SAG_C
Normally zero. Becomes one when |VB| remains below SAG_THR for SAG_CNT
samples. Will not return to zero until |VB| rises above SAG_THR.
SAG_B
SAG_A
Normally zero. Becomes one when |VA| remains below SAG_THR for SAG_CNT
samples. Will not return to zero until |VA} rises above SAG_THR.
25
24-0
Not Used These unused bits will always be zero.
For generating proper status information, the CE is initialized by the MPU using SAG_THR (default of 80V RMS at the meter
input if VMAX=600V) and SAG_CNT (default 80 samples). Using the default value for SAG_CNT, the peak-to-peak signal has to
be below SAG_THR value for 32 milliseconds to activate the SAG_X status bits.
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