Rainforest Automation EMU-2 Technical Manual - Emu-2
EMU-2
™
Technical Manual
21
Prepay Support
A firmware option is available for EMU-2
™ to read the Prepayment Cluster (see the
Supported Clusters diagram in the
“About the EMU-2” section in this manual). If this is
enabled in the firmware build, then the Prepayment Information attribute set is read from
the meter. If the meter provides this information, then a new Prepaid Balance screen is
shown between the Current Price screen and the Message screen:
If the meter does not support the Prepayment Cluster, the EMU-2
™ can still receive the
Prepaid Balance information by using specially formatted text messages. This technique
is called Message Tunneling. A text message can be sent to the Meter Control System,
containing the account balance information, as well as a time stamp and corresponding
meter reading, along with the appropriate meter number. The Meter Control System
can forward the text message in the usual way to the meter, and the meter will deliver
the text message via ZigBee to the EMU-2
™.
If Message Tunneling support is enabled in the EMU-2
™, then the incoming text
message is scanned, looking for the following pattern:
PREPAID BALANCE= $xxx.xx (mm/dd/yyyy-hh:mm:ss) zzzzzkWh
Where:
xxx.xx is the account balance in dollars
mm/dd/yyyy-hh:mm:ss is the date and time stamp
zzzzz is the last 5 digits of the meter reading
The information in the text message provides the data necessary for the EMU-2
™ to
provide the Prepaid Balance screen. The EMU-2
™ can even estimate the up-to-date
Prepaid Balance
$503.48
Customer
Database
AMI
Network
Meter
Control
System
Meter #
Text Message
Account Balance
Meter Reading
Smart Meter
Text
Message
EMU-2
™