User's Manual

VRT TRANSPONDER OVERVIEW
VRT Transponder—User Guide Page 7
AMCO Automated Systems, January 2003 Last Saved: 1/28/2003 10:00 AM
How the Pit Water Transponder Works
The transponder polls the water meter register/encoder for the meter
reading and stores this value in the transponder’s memory. The interval
at which the transponder polls the register/encoder is referred to as the
encoder latency and is programmable by the user. The default value for
the encoder latency is 1 hour. When the transponder receives an
interrogation signal, the transponder transmits the latest meter reading
stored in memory to the interrogator.
Once a day, at a pre-programmed time, the transponder stores the
current index reading for that day into the e-index for that day. The
transponder maintains daily reading history for the past 35 days. Four
time-of-use registers with programmable start and stop times can
accumulate consumption in separate e-indexes as well.
To maximize battery life, the transponder changes from its normal, low-
power quiescent state every 1.5 seconds into an intermediate power
state for 2.5 milliseconds in order to (1) update the e-index for the meter
index, daily reading and time-of-use indexes; perform tamper detection;
and (3) check to see if a valid interrogation signal is being received.
When a valid interrogation signal (including the transponder’s unique
serial number) is received, a two-way communication link is established.
A current reading and other historical data (as required for each
individual account) is transmitted to the interrogator. Data collected by
an interrogator are validated, audited and stored for uploading to
TRACE® Route Manager VRT Software later.
VRT™ Transponder Program Values.
At the time of manufacture transponders are programmed with the
current date, time of day, and other values as specified by the utility.
Time of Day. The time of day for the time zone specified by the utility is
programmed into the transponder. The time of day on the transponder
can be synchronized with the clock in the interrogation device each time
the transponder is read.
Daylight Savings Time. If daylight savings time is observed the utility
must advise AMCO Automated Systems and the initial settings will be
programmed into the transponder at the time of manufacture. Updates
to daylight savings time will be communicated through Route Manager
VRT ™ and interrogators.
Daily Read Capture Time. Daily read history is recorded at the same
time each day for retrieval at a later date. The daily read capture time is
specified by the utilty and programmed into the transponder at time of
manufacture.
Time of Use Registers. Time of use registers, if activated, accumulate
consumption recorded by the transponder between the start and stop
time set for each TOU register. If activated the TOU register must be
active for a minimum of 00:29:59 (hh:mm:ss) and a maximum of
23:44:59 (hh:mm:ss). TOU registers can start on the hour or in 15-
minute intervals after the hour (12:15:00 PM is a valid start time /