Echelon Neuron C - Manual (Page 201)

Neuron C Programmer’s Guide 189
By default, the address table contains 15 entries. Each address table entry uses
five bytes of on-chip EEPROM. Use the following compiler directive to decrease
the number of address table entries:
#pragma num_addr_table_entries nn
( nn can be any value from 0 to 15)
The maximum number of address table entries that a device could require is
bounded by the maximum expected number of different destination entries
required by connections (both network variables and message tags) for that
device. A destination entry is required for an output network variable or
message tag in a connection, if the output is not declared as a polled output, and
also for the input if the input is polled or a member of a group connection. Two
destination entries differ if they use a different service type, a different
destination address, or different transport attributes (such as the repeat timer).
Multiple network variables that use the same destination entry share a common
address table entry. Fewer address table entries are consumed when address
table entries can be shared by multiple connections. This capability can only be
used if the network tool used to install the device generates shared entries (all
LNS tools, including the LonMaker Integration Tool, provide this capability).
As a general rule, the address table should be sized to the maximum of 15
entries, if possible.
Alias Table
The alias table is generated according to the alias table size specified with the
#pragma num_alias_table_entries compiler directive, shown below. This
compiler directive can be used to set the alias table size to any size between zero
and 127 entries. Each alias entry uses 4 bytes of EEPROM (on-chip for Series
3100 devices or offchip for Series 5000 devices). An alias is an abstraction for a
network variable that is managed by network tools and the Neuron firmware.
Network tools use aliases to create connections that cannot be created solely with
the address and network variable tables, providing network integrators with
more flexibility in how devices are installed into networks. This feature requires
Neuron firmware version 6 or later.
#pragma num_alias_table_entries nn
(see Table 13 for the maximum value of nn )
How many network variable aliases a Neuron-hosted device can support depends
on the device’s memory map, the system firmware, and the development tool
version, as shown in Table 13.
Table 13. Alias Limits
Neuron System
Firmware Version
NodeBuilder
Development Tool
Version
Maximum Number of
Aliases
Version 15 or earlier Any 62
3.1 or earlier 62
Version 16 or later
FX or later 127