User's Manual

COMPANY CONFIDENTIAL
RF-TWACS Based AMR System DCSI CUSTOMER PRODUCT SPECIFICATION
May 30, 2003 Application Notes – Rev. 1 21
4.3 RF-TWACS System Software – Central Communication Equipment
4.3.1 Data Available From Meters
The system is designed to supply a total consumption reading from each meter that has
been frozen at a specific time of day on a daily basis. Furthermore, the system can deliver
at any time, an “on-demand” or “Present” total consumption reading for each meter. The
“present” gas or water reading will be pulled from the electric meter. The data in the
electric meter is updated hourly.
4.3.2 CCE Data Requirements
4.3.2.1 Initial Installation
The CCE need only know that an EMA with RF capability has been installed. It will
“search” the meter and install it into a daily AMR schedule. If and when RF-TWACS
devices are installed at the same location, and the installer configures an EMTR (and
consequently the hosting EMA) to accept an RMTR, a flag will be set indicating a change
in the configuration tables. The CCE may then read various registers to self-discover the
type of service and serial number of the RMTR.
4.3.2.2 Change-outs
The requirements are the same as for initial installation.
4.3.3 Data Availability
4.3.3.1 During Outage
Data cannot be conveyed over the TWACS system during an outage. RMTR’s will
attempt to upload data to EMTR’s using RF, but be unsuccessful because EMTR’s are
powered from the powerline.
4.3.3.2 During non-RF communications
As described earlier, radio communications are kept to a minimum in an effort to
preserve battery life. The EMTR and EMA maintain data on behalf of the RMTR. The
design intends for data to be updated every hour. The latest RMTR data is readily
available from the EMA via the TWACS.
4.3.3.3 Lost Data
It is possible that in some instances, RF conditions will prevent communications from
occurring between an RMTR and an EMTR every hour. In this case the “present total
consumption” reading maintained in the EMTR will be the last successful reading, not
the latest top-of-the-hour present reading.
It is possible that the frozen daily read can be affected by adverse RF propagation
conditions. In this case, the frozen daily read will be obsolete until radio communication
is restored.
Once RF communication is restored, the “present” total consumption reading will be
updated in the EMTR, and if necessary, the daily frozen reading as well.