Rainbow Electronics 71M6542G - Manual (Page 93)

v1.1 © 2008–2011 Teridian Semiconductor Corporation 93
4.3 71M6541D/F Using Local Sensors
Figure 35 shows a 71M6541D/F configuration using locally connected current sensors. The IAP-IAN
current channel may be directly connected to either a shunt resistor or a CT, while the IBP-IBN channel is
connected to a CT and is therefore isolated. This configuration implements a single-phase measurement
with tamper-detection using one current sensor to measure the neutral current. This configuration can
also be used to create a split phase meter (e.g., ANSI Form 2S). For best performance, both the IAP-IAN
and IBP-IBN current sensor inputs are configured for differential mode (i.e., DIFFA_E = 1 and DIFFB_E =
1, I/O RAM 0x210C[4] and 0x210C[5]). The IBP-IBN input must be configured as an analog differential
input disabling the remote sensor interface (i.e., RMT_E = 0, I/O RAM 0x2709[3]). See
Figure 2 for the AFE
configuration corresponding to Figure 35 .
MPU
RTC
TIMERS
IAP
VA
IBP
XIN
XOUT
RX
TX
TX
RX
COM0...5
V3P3A V3P3SYS
VBAT
VBAT_RTC
SEG
GNDA GNDD
SEG/DIO
DIO
ICE
LINE
NEUTRAL
LOAD
8888.8888
PULSES,
DIO
IR
AMR
POWER FAULT
COMPARATOR
MODUL-
ATOR
SERIAL PORTS
OSCILLATOR/
PLL
MUX and ADC
LCD DRIVER
DIO, PULSES
COMPUTE
ENGINE
FLASH
MEMORY
RAM
32 kHz
REGULATOR
CT
POWER SUPPLY
TERIDIAN
71M6541D/F
TEMPERATURE
SENSOR
VREF
BATTERY
PWR MODE
CONTROL
WAKE-UP
NEUTRAL
I
2
C or µWire
EEPROM
IAN
IBN
RTC
BATTERY
V3P3D
BATTERY
MONITOR
SPI INTERFACE HOST
LCD DISPLAY
Resistor Divider
CT
LINE
LINE
Note:
This system is referenced to LINE
Shunt
or
11/5/2010
Figure 35. 71M6541D/F with Local Sensors