Rf Transmitter; Logic Control; Transmitter; Power Supply - Schlumberger RoadMAPS User Manual

RoadMAPS Overview

RF Transmitter

Power Supply

2-16

Logic Control

The logic control module takes the information gathered from the
PPC through the CPU and sets the operating transmit frequency
and the required tone for that information. It also monitors the
unit temperature and will stop the operation of the unit if the tem-
perature falls outside the specified temperature range, not to
exceed 70°C. This will limit the operation of the unit to about 50°C
ambient termperature.
The logic control also generates the modulating waveform for use
by the transmitter module. The modulatig tones will be chosen
from 15 frequancies between 24 Hz and 58 Hz.

Transmitter

The transmitter module generates a frequency and applies the
modulating waveform created by the logic control module. It then
amplifies the signal with a modulation index greater than 99%. The
RF energy, up to 10W of RF power, is sent to the antenna through
the duplexer. As with the RF receiver, the duplexer ensures that
the transmitting signal is passed from the RF transmitter to the
antenna.
The RF transmitter is, by default, inactive. It will operate on any
one of 1760 RF channels between 951 MHz and 962 MHz with 6.25
kHz channel spacing and, once actiated, will be used to continu-
ously send a wakeup/alert tone to the R100 and R200 MIUs or the
ITRON ERTs. The RF frequency and the alert tone frequency will
both be programmed from the PPC.
The RoadMAPS Unit is powered by a 12V automobile battery, but
both the RF receiver and the RF transmitter are supplied power
from that battery through independent paths. Refer to the follow-
ing table for the different operating voltages and current levels.
RoadMAPS User's Manual