71M6533 Datasheet, PDF (95/124 Pages) Teridian Semiconductor Corporation – Energy Meter IC

FDS_6533_6534_004
[0]
PULSE_SLOW
71M6533/71M6534 Data Sheet
0
ther 1 or 0. Default is 0 for both (X = 6).
PULSE_SLOW
0
0
1
PULSE_FAST
0
1
0
X
1.5 * 2² = 6
1.5 * 2⁶ = 96
1.5 * 2^-4 = 0.09375
1
1
Do not use
CE Ad-
dress
0x24
0x40
Table 54: Sag Threshold and Gain Adjust Control
Name
SAG_THR
GAIN_ADJ
Default Description
2.39*10⁷
16384
The voltage threshold for sag warnings. The default value is
equivalent to 80 V RMS if VMAX = 600 V.
This register scales all voltage and current channels. The
default value is equivalent to unity gain (1.000).
4.3.8 CE Transfer Variables
When the MPU receives the XFER_BUSY interrupt, it knows that fresh data is available in the transfer
variables. CE transfer variables are modified during the CE code pass that ends with an XFER_BUSY
interrupt. They remain constant throughout each accumulation interval. In this data sheet, the names of
CE transfer variables always end with _X. The transfer variables can be categorized as:
1. Fundamental energy measurement variables
2. Instantaneous (RMS) values
3. Other measurement parameters
Fundamental Energy Measurement Variables
Table 55 describes each transfer variable for fundamental energy measurement. All variables are signed
32-bit integers. Accumulated variables such as WSUM are internally scaled so they have at least 2x mar-
gin before overflow when the integration time is one second. Additionally, the hardware will not permit
output values to fold back upon overflow.
CE Ad-
dress
0x85
0x86
0x87
0x88
0x8A
0x8B
0x8C
0x8D
Name
WSUM_X
W0SUM_X
W1SUM_X
W2SUM_X
VARSUM_X
VAR0SUM_X
VAR1SUM_X
VAR2SUM_X
Table 55: CE Transfer Variables
Description
The signed sum: W0SUM_X+W1SUM_X+W2SUM_X.
The sum of Wh samples from each wattmeter element.
LSB = 9.4045*10^-13 VMAX IMAX / In_8 Wh.
The signed sum: VAR0SUM_X+VAR1SUM_X+VAR2SUM_X.
The sum of VARh samples from each wattmeter element.
LSB = 9.4045*10^-13 VMAX IMAX / In_8 VARh.
WxSUM_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. 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.
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