User Manual

CHAPTER 3 VRT DIRECT GAS-METER TRANSPONDER OVERVIEW
EnergyAxis Gas Module ― User Guide Page 9
Elster Integrated Solutions • Draft Rev A Nov. 2007
How the EnergyAxis Direct Gas-meter
Transponder Works
When a EnergyAxis DGT is installed on a meter the installer
programs the mechanical index reading into the transponder.
Converting Mechanical Count into Electronic Form
During normal operation, the mechanical index accumulates its
count. The transponder keeps track of the index reading by counting
the number of rotations of the index’s drive dial.
Storing Readings
Once a day, at a pre-programmed time specified by the utility, the
transponder stores the current index reading into the electronic
index for that day.
The transponder maintains daily reading history for the past 35
days.
Between 1 an 4 interval values per hour—can accumulate
consumption in separate electronic indexes as well.
Operation Cycle
To maximize battery life, the EnergyAxis gas-meter transponder
changes from its normal, low-power quiescent state every 2
seconds into an intermediate power state for 5.5 milliseconds in
order to perform three tasks:
• Update the electronic indexes for the meter reading, daily
reading and interval reading
• Poll the tamper detection switch
• Check to see if a valid interrogation signal is being received
If and when a valid interrogation signal is received, a two-way
communication link is established.
Meter reading data is then transmitted to the interrogator.
Data collected by an interrogator is validated and stored for
uploading to Route Manager Software later.