71M6543F Maxim, 71M6543F Datasheet - Page 125

• Manufacturer Part Number: 71M6543F
• Description: The 71M6543F/71M6543H are Teridian's 4th-generation polyphase metering system-on-chips (SoCs) with a 5MHz, 8051-compatible MPU core, low-power real-time clock (RTC) with digital temperature compensation, flash memory, and LCD driver
• Manufacturer: Maxim

interrupt. They remain constant throughout each accumulation interval. In this data sheet, the names of
•
Fundamental Energy Measurement Variables
Table 80
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 does not permit
The CE pulse generator can be controlled by either the MPU (external) or CE (internal) variables. Control is by
the MPU if the EXT_PULSE bit = 1 (CE RAM 0x20[5]). In this case, the MPU controls the pulse rate (external
pulse generation) by placing values into APULSEW and APULSER (CE RAM 0x45 and 0x49). By setting
EXT_PULSE = 0, the CE controls the pulse rate based on WSUM_X (CE RAM 0x84) and VARSUM_X (CE
RAM 0x88).
5.4.8 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
CE transfer variables always end with _X. The transfer variables can be categorized as:
•
•
output values to fold back upon overflow.
Address
v1.2
0x8A
0x8B
0x84
0x85
0x86
0x87
0x88
0x89
Address
CE
Fundamental energy measurement variables
Instantaneous (RMS) values
Other measurement parameters
0x24
0x40
0x41
0x42
0x43
0x44
CE
The 71M6543 Demo Code creep function halts both internal and external pulse generation.
describes each transfer variable for fundamental energy measurement. All variables are signed
VAR0SUM_X
VAR1SUM_X
VAR2SUM_X
VARSUM_X
W0SUM_X
W1SUM_X
W2SUM_X
WSUM_X
GAIN_ADJ0
GAIN_ADJ1
GAIN_ADJ2
GAIN_ADJ3
GAIN_ADJ4
Name
SAG_THR
Table 79: Sag Threshold, Phase Measurement, and Gain Adjust Control
Name
© 2008–2011 Teridian Semiconductor Corporation
The signed sum: W0SUM_X+W1SUM_X+W2SUM_X.
The sum of Wh samples from each wattmeter
element.
The signed sum:
VAR0SUM_X+VAR1SUM_X+VAR2SUM_X.
The sum of VARh samples from each wattmeter
element.
Table 80: CE Transfer Variables (with Shunts)
2.39*10
Default
16384
16384
16384
16384
16384
LSB
LSB
W
W
7
= 7.7562*10
= 7.7562*10
Description
The voltage threshold for sag warnings. The default value is
equivalent to 80 V RMS if VMAX = 600 V.
The assignments of these gain adjustments depends on the
meter design. See
and Shunt Sensors
Compensation of VREF and Current Transformers
The default value of 16384 corresponds to unity gain.
Description
-13
-13
VMAX * IMAX Wh.
VMAX * IMAX VARh.
4.5.5 Temperature Compensation for VREF
71M6543F/H and 71M6543G/GH Data Sheet
on page
90
or
4.5.6 Temperature
Figure 31
Configuration
on page
(page 87)
92.
125