Echelon Neuron C - Manual (Page 197)

Neuron C Reference Guide 177
A message tag declaration can optionally include connection information. The
syntax for declaring a message tag is as follows:
msg_tag [ connection - info ] tag - identifier [, tag - identifier ...];
The connection-info field is an optional specification for connection options, in the
following form:
bind_info ( options )
The following connection options apply to message tags:
nonbind Denotes a message tag that carries no implicit addressing
information and does not consume an address table entry.
It is used as a destination tag when creating explicitly
addressed messages.
rate_est ( const-expr ) The estimated sustained message rate, in tenths of
messages per second, that the associated message tag is
expected to transmit. The allowable value range is from 0
to 18780 (0 to 1878.0 messages/second).
max_rate_est ( const-expr ) The estimated maximum message rate, in tenths
of messages per second, that the associated message tag is
expected to transmit. The allowable value range is from 0
to 18780 (0 to 1878.0 messages/second).
tag-identifier A Neuron C identifier for the message tag.
It might not always be possible to determine rate_est and max_rate_est. For
example, message output rates are often a function of the particular network
where the device is installed. These optional values can be used by a network
tool to perform network device analysis. Although any value in the range
0-18780 can be specified, not all values are used. The values are mapped into
encoded values n in the range 0-127. Only the encoded values are stored in the
device’s self-identification (SI) data. The actual value can be reconstructed from
the encoded value. If the encoded value is zero, the actual value is undefined. If
the encoded value is in the range 1-127, the actual value is:
5 ) 8 / (
2
− = n
a
rounded to the nearest tenth. The actual value, a , produced by the formula, is in
units of messages per second.
You must assign a message tag to the msg_out.tag field for each outgoing
message. This specifies which connection point (corresponds to an address table
entry) to use for the outgoing message. After the tag field has been assigned, the
message must be either sent or cancelled.