User Manual

Table Of Contents
On Air Message Types 4-5
SmartPoint Module for the Elster A3 Meter ECMTM40000
4.5.1.1 Latitude
These fields contain a representation, in degrees of the end point device’s installation latitude as
presented by the attached GPS module. The actual latitude can be calculated using the following
formula:
Latitude (degrees) = (3 Byte App Data Latitude) * 90.0/8388608
Negative values are in the southern hemisphere; positive values are in the northern hemisphere.
Longitude
These fields contain a representation in degrees of the end point device’s installation longitude as
presented by the attached GPS module. The actual longitude can be calculated using the
following formula:
Longitude(degrees) = (3 Byte App Data Longitude) * 180.0 / 8388608
Negative values are in the western hemisphere, positive values are in the eastern hemisphere.
For example, an App Data Latitude of 0x bff2d7 yields a latitude in degrees of -90.07229, or
90.07229 West.
4.5.1.2 Speed
This field contains the velocity of the endpoint device in 0.01 knot resolution and is sent LSB first.
4.5.1.3 Heading
This field contains the device’s heading in 0.01 degree resolution and is sent LSB first.
4.5.1.4 Altitude
This field contains the device’s altitude in 0.1 meter resolution.
4.6 Command Message—App Code 7
4.6.1 Message Format
This is a Command Message sent by a TGB ( Tower Gateway Basestation ) or a repeating two-way
device. The format of bytes 1-27 are variable based upon command type.
4.6.2 Command Type
This field contains the type of data in the command as shown below, specific formats for each
message can be found in Section 6.2, Receiver On-Air Command Formats.
App Data
Byte
0 1 - 27
Data Command Type Command Data