Echelon LNS - Manual (Page 169)

LNS Programmer's Guide 155
AliasOptions Values BroadcastOptions
Values
lcaAliasForSelectorConflicts lcaAliasForUnicasts
lcaBroadcastGroup If the connection is using the
acknowledged messaging service,
this combination allows for
subnet/node addressing and
group addressed multicast
connections. The
unacknowledged/repeat
messaging service also allows
subnet broadcast addressing to be
used, and the unacknowledged
messaging service further allows
the use of domain broadcast
addressing.
This combination splits a
single multicast connection
into multiple unicast
connections using subnet/node
addressing, and allocates
aliases to the output network
variable. If no aliases are
available, LNS will use group
addressing instead. If no
aliases and no group IDs are
available and the service type
is unacknowledged, LNS will
use subnet or domain wide
broadcast addressing. If no
aliases and no group IDs are
available and the service type
is unacknowledged/repeat,
LNS will use subnet
broadcasting if possible.
lcaBroadcastAlways This combination is
recommended if multicast
connections must be used, and
group addressing needs to be
avoided.
This combination splits single
multicast connections into
multiple unicast connections,
but uses broadcast addressing
for each of the unicast
connections. This has the
advantage of potentially re-
using address table space on
the sending node, at the
expense of network
bandwidth.
Example Connection Scenario: Building Controls
Figure 7.3 depicts a connection created to manage a lighting system in an office building.
The example includes 9 lamps in the ceiling, identified with letters A through J. There
are also 4 occupancy sensor devices identified with letters R through U, each connected
to the four surrounding lamps. Thus, occupancy sensors R and S necessarily are both
connected to lanterns B and E, sensors R and T share lamps D, E, and so on. This
common scenario presents an interesting problem.