in this link MassaBUS incontra Arduino - Massari Electronics you can read
the scematic,
i connect whit a tisted wire the A connector of shiled and A connector of Energy monitoring and the B connector of shiled with B connector of Energy monitoring.
The energy monitor is work well because i use a "TCP/IP Ethernet to Serial RS232 RS485 RS422 Converter" for comunicat with it,
i use this program: modpoll
modpoll -1 -f -m enc $IP -p $PORT -a $ADDR -c $CARD -r $PARAM
this is my configuration:
IP=192.168.1.121
PORT=2000
ADDR=31
PARAM=4
CARD=2
now i hope answer all you request