Product Info

4 On-Demand 1.2 Overview
Technical Brief
DCUs
The DCU acts as an intermediary device. It gathers readings from MTUs and
transmits those readings, as well as system diagnostic information such as signal
strength and battery power, back to AclaraONE. This data may be encrypted for
additional security, though encryption is not necessary.
This interface to AclaraONE is known as the backhaul, and it is typically via
cellular data service, though other technologies such as Wi-Fi, fiber optics, and
Ethernet can also be used. Typically a cellular backhaul DCU will make several
calls a day to transmit data to AclaraONE. Those using Wi-Fi, Ethernet or fiber
optics will be in Always On mode, so data flows across the backhaul as it comes in
from the MTU network and as AclaraONE issues commands back.
Raised a minimum of 30 feet off the ground, DCUs are installed on a half-mile to
one-mile grid. When installing a new system, Aclara’s Global Information
Service, or GIS department, will conduct a site survey to determine the location for
all DCUs in the system for optimum radio reception. Factors such as topography
and building density will affect reception and DCU placement.
Because the signal range of a standard MTU is a half-mile to a mile, each MTU
transmission will typically reach multiple DCUs. This creates additional
redundancy in the system, so if a DCU were to be temporarily out of service, the
readings from MTUs near it will still be collected by neighboring DCUs.
In order to achieve the elevation required to allow MTU transmissions to reach
them, DCUs are typically installed on utility poles, microwave or cellular towers,
water towers, water tanks, or flat roofs.
The DCU has several components. These include a pair of antennas mounted on a
boom, which connect via cables to a metal cabinet that contains a number of circuit
boards, radio receivers, and a battery to power its operation. The battery is charged
by AC or solar power. If the battery is solar powered, then the third component of
the DCU will be a solar panel. If the battery is AC powered, there will be no solar
panel.
The DCU cabinet is typically mounted near the antennas and solar panel, high off
the ground for security. In locations where there is a security fence or other secure
enclosure, the DCU cabinet may be mounted near ground level for user
convenience.
Inside the DCU cabinet is a 12-volt battery that powers its operation. There are
also ports for the incoming power source and for the incoming antenna cables.
Additionally there is a metallic cylinder is called a bandpass filter. This filter is
tuned to the FCC-licensed frequency in use by the system, so only signals on that
very narrow band will be received. Lastly there is a weatherproof enclosure
containing the printed circuit boards.