71M6534 MAXIM [Maxim Integrated Products], 71M6534 Datasheet - Page 100

• Manufacturer Part Number: 71M6534
• Description: Exceeds IEC 62053/ANSI C12.20 Standards
• Manufacturer: MAXIM [Maxim Integrated Products]

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:
2. Instantaneous (RMS) values
3. Other measurement parameters
Fundamental Energy Measurement Variables
Table 60
32-bit integers. Accumulated variables such as WSUM are internally scaled so they have at least 2x
margin before overflow when the integration time is one second. Additionally, the hardware will not
permit output values to fold back upon overflow.
5.3.8 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
1. Fundamental energy measurement variables
100
Address
Address
0x8C
0x8D
0x8A
0x8B
0x85
0x86
0x87
0x88
0x24
0x40
CE
CE
[1]
[0]
describes each transfer variable for fundamental energy measurement. All variables are signed
PULSE_SLOW
PULSE_FAST
VAR0SUM_X
VAR1SUM_X
VAR2SUM_X
GAIN_ADJ
VARSUM_X
SAG_THR
W0SUM_X
W1SUM_X
W2SUM_X
WSUM_X
Name
Name
Table 59: Sag Threshold and Gain Adjust Control
2.39*10
Default
16384
Description
The signed sum: W0SUM_X+W1SUM_X+W2SUM_X.
The sum of Wh samples from each wattmeter element. In_8 is the
gain 1 or 8 as configured by In_SHUNT.
The signed sum: VAR0SUM_X+VAR1SUM_X+VAR2SUM_X.
The sum of VARh samples from each wattmeter element. In_8 is the
gain 1 or 8 as configured by In_SHUNT.
0
0
Table 60: CE Transfer Variables
LSB = 9.4045*10
LSB = 9.4045*10
7
When PULSE_FAST = 1, the pulse generator input is increased
16x. When PULSE_SLOW = 1, the pulse generator input is
reduced by a factor of 64. These two bits control the pulse
gain factor X (see table below). Default is 0 for both (X = 6).
PULSE_SLOW PULSE_FAST
Description
The voltage threshold for sag warnings. The default value is
equivalent to 80 V RMS if VMAX = 600 V. The LSB value is
VMAX * 7.8798*10
V RMS is required:
This register scales all voltage and current channels. The
default value is equivalent to unity gain (1.000).
SAG
_
0
0
1
1
THR
-13
-13
=
VMAX IMAX / In_8 Wh.
VMAX IMAX / In_8 VARh.
VMAX
-9
V. For example, if a sag threshold of 80
80
⋅
0
1
0
1
. 7
⋅
8798
2
⋅
10
1.5 * 2
−
9
=
1.5 * 2
1.5 * 2
Do not use
. 2
-4
39
X
= 0.09375
6
⋅
2
10
= 96
= 6
7
Rev 2