Echelon DM-21 Device Manager - Manual (Page 8)

1-4 DM-20/21 Overview
www.echelon.com/products/DM. The Device Manager’s internal event log can be
retrieved using a service tool to assist with diagnosing problems.
Periodically, the device manager will search the network for new devices. Any
newly found or replacement devices will be integrated into the network as soon as
they are detected. The Device Manager will automatically establish or, in the
case of a replacement, re-establish all connections with other devices.
Allowable Topologies
A Device Manager can support single or dual channel networks. In a single
channel network, the channel must be a TP/FT-10 free topology channel. In a
dual channel network, the Device Manager must be attached to a TP/FT-10
channel, however the second channel (on the far side of the router) may be of any
type of L
ON W ORKS channel. The use of a single router is supported in this
topology.
DM
DM
Router
Single Channel Dual Channel
Figure 1.2 – Using a Device Manager in Single and Dual Channel networks
Using Subsystems
For large systems, it is possible to use multiple Device Managers to manage the
network. For example a train might use one Device Manager per car, or a
building might use one Device Manager per floor. Although several Device
Managers are working together to manage a larger system, the same topology
rules apply to each device manager.
DM
Router
DM
Router
DM
Router
Subsystem 1 Subsystem 2 Subsystem 3
Backbone
Channel
Figure 1.3 – Multiple Device Managers working together - Legal
Topology
Figure 1.3 illustrates the use of three Device Managers working together to
manage a large system. When a LonMaker drawing is made, all of the devices in
the system are placed on the drawing (including the three routers and the three