User Manual

Table Of Contents
On Air Message Format 3-3
SmartPoint Module for the Elster A3 Meter ECMTM40000
3.1.7 Repeat Level / Status
3.1.8 Application Sequence
An 8 bit modulo 256 counter that increments every time new application data is transmitted by the end
point device.
3.1.9 Application Code
An 8 bit code used to determine the format of the data in the Application Data field.
3.1.10 Application Data
Between 0 and 252 bytes of application data in the future, fixed at 28 for now.
3.1.11 CRC
The 32 bit CCITT Cyclical Redundancy Check sum of all of the bytes from the ID field to the last
Application Data field. Allows for bit error detection and single bit error correction.
3.2 On Air Time Requirements
On air messages take differing amounts of airtime depending on modulation format. The message length of
every message is fixed at 31 bytes. The table below shows the transmission time for each combination:
Bits Repeat Level / Status
0 History Overflow
1In Time Sync
2Tamper
3Brown Out
4 Meter Read Failure
5 RF Sequence Number MSB
6-7 Repeat Level
Modulation Error Correction
Rate
(Hz)
Msg Time
(msec)
Normal Baud Interleaved, Convolutionally
Encoded
8044.5544 107.40
mPass Baud Interleaved, Convolutionally
Encoded
5000.0000 157.60
Boost Baud Interleaved, Convolutionally
Encoded
804.4554 1074.02
Half Baud Interleaved, Convolutionally
Encoded
4022.2772 214.80