Technical Manual

Chapter 3 • Introduction
D C U M a i n t e n a n c e a n d O p e r a t i o n M a n u a l 13
Fiber
A direct fiber connection is also available in the DCU 2+. See additional details in
the DCU Installation Instructions, Y20977-TUM for details on wiring and
connection. A fiber connected DCU supports up to a 100 Mbps data speed.
Failover Backhaul
Failover backhaul is a feature that Aclara’s DCU 2+ now provides as a means to
switch between a primary and secondary backhaul should the primary backhaul
fail. This variation of the DCU 2+ allows a combination of a Cellular and Ethernet
or Fiber backhaul.
Once a DCU is connected, the DCU uses periodic messages from the headend to
ensure connectivity. If the DCU does not receive these commands within the
specified duration, the backhaul is considered to be down. At this point, the active
connection is terminated and secondary backhaul is activated.
The DCU defaults to periodically checking for the primary backhauls available
through the Automatic Recovery Mode option. The user also has the option to
manually control when to switch back to the primary backhaul through the
AclaraOne user interface in the event of a planned outage. The DCU defaults to the
Automatic Recovery Mode Option on a 6 hour duration.
It is important to note that failover backhaul functionality is enabled by default
when both a Cellular and Ethernet/Fiber card are detected. In a situation where a
DCU is populated with both backhauls, but one of the backhauls is not set up -
either a physical line has not been not run to the DCU yet, or the cell phone has
purposely not been activated - the failover backhaul feature can be disabled
through the local installer menu. Disabling the functionality will prevent the DCU
from trying to connect to a backhaul that is not set up, which will allow a faster
reconnection time with the headend in the event the connection is dropped.
System Prerequisites
• AclaraOne 1.9
• Mainboard FW – 3.20.0012
• T-Board FW - 1.71.0054
Solar
Fiber optic and failover DCUs consume more power than a standard cellular or
Ethernet configuration. Please check with Aclara regarding solar capability for
your region.
Transceiver Board Options
The DCU II+ supports multiple transceiver cards based on the RF requirements of
the network. Each transceiver board is programmed at the factory using the
customer’s licensed frequency information and desired security configuration.