User's Manual

COMPANY CONFIDENTIAL
RF-TWACS Based AMR System DCSI CUSTOMER PRODUCT SPECIFICATION
May 30, 2003 Application Notes – Rev. 1 15
Coding: Manchester encoding (3200 bps)
Data Rate: 1600 bps
Data Encryption: DCSI proprietary method #1
Maximum Packet size: Complies with FCC rules.
Max. Packet Transmission time: Complies with FCC rules.
4.2.3.2 Initial Installation and Change-outs
The intent of this section is to provide general guidelines for the initial installation and
subsequent troubleshooting and replacement of EMTR units.
A Centron meter that has been outfitted with the EMT-3C-MP and EMTR modules is
both TWACS and RF-TWACS capable. If they are deployed in advance of the RMTRs,
then the electric metering capability of the Centron meter may still be used prior to
deployment of any gas or water metering.
If a Centron meter has been initially deployed without an EMTR, it always can be
converted later, at the meter shop, to a radio-capable unit by plugging in an EMTR and
properly initializing the assembly.
The change-out procedure for a failed EMTR is the nearly same as described below in
Section 4.2.4.2.3 – EMTR Installation. If the installer finds that the EMTR is still alive, it
is advisable that he use the HHTR to first upload the “Acquisition List” table from the
unit, swap it out, then download the same Acquisition List into the new unit.
If on the other hand, the installer finds that the EMTR is not functional, he must treat this
as a new installation and load the Acquisition List with the proper assignments. The only
way to know for sure which assignments are necessary is for him to be armed with this
information from the CCE before he goes out into the field. All RMTRs that were
assigned to the old EMTR need to be assigned to the new EMTR (or other EMTRs) in
order to restore network integrity.
4.2.3.3 EMTR Operations
Creation of a Session
The EMTR scans acquisition channels and determines the average RSSI energy level. If
the EMTR hears a channel which contains energy significantly above the average, it stops
on that channel and attempts to establish communication. If it cannot do this successfully,
the EMTR abandons the channel and resumes scanning. If it decodes a valid packet, and
it is an RTS from an HHTR or from an RMTR for which it is responsible, it replies with a
Clear-to-Send (CTS) packet or with a valid command packet.
Data Transmission
After the EMTR accepts the RTS, it takes control of the session and issues commands to
harvest data.
Additional exchanges may occur between the two devices, limited only by FCC rules.
The data field in packets is encrypted (with the exception of RTS and CTS packets).
Session Conclusion (with an RMTR)