Rainbow Electronics 71M6542G User Manual

Page 13

v1.1

shows the 71M6541D/F multiplexer interface with one local and one remote resistive shunt

sensor. As seen in

, when a remote isolated shunt sensor is connected via the 71M6x01, the

samples associated with this current channel are not routed to the multiplexer, and are instead
transferred digitally to the 71M6541D/F via the digital isolation interface and are directly stored in CE
RAM.

See

Figure 6

for the multiplexer timing sequence corresponding to

Figure 3

. See

Figure 36

for the meter

configurations corresponding to

Figure 3

∆Σ ADC

CONVERTER

VREF

MUX

VREF

VADC

FIR

IBP

IAP

VADC10 (VA)

IAN

IBN

71M6541D/F

CE RAM

71M6x01

INP

INN

Remote

Shunt

IN*

Digital

Isolation

Interface

Local

Shunt

LINE

11/5/2010

* IN = Optional Neutral Current

Figure 3. 71M6541D/F AFE Block Diagram with 71M6x01

Figure 4

shows the 71M6542F AFE with locally connected sensors. The analog input signals (IAP-IAN,

VA, IBP-IBN and VB) are multiplexed to the ADC input and sampled by the ADC. The ADC output is
decimated by the FIR filter and stored in CE RAM where it can be accessed and processed by the CE.

See

Figure 7

for the multiplexer timing sequence corresponding to

Figure 4

. See

Figure 37

for the meter

configuration corresponding to

Figure 4

∆Σ ADC

CONVERTER

VREF