Echelon FTXL - Manual (Page 52)

40 Creating a Model File
Declaring a Message Tag
You can declare a message tag in a model file. A message tag is a connection
point for application messages. Application messages are used for the
L
ON W ORKS file transfer protocol, and are also used to implement proprietary
interfaces to L ON W ORKS devices as described in Chapter 5, Developing an FTXL
Application , on page 73.
Message tag declarations do not generate code, but result in a simple
enumeration, whose members are used to identify individual tags. There are two
basic forms of message tags: bindable and nonbindable.
Example:
msg_tag myBindableMT;
msg_tag bind_info(nonbind) myNotBindableMT;
Similar to network variables, you can connect bindable message tags together,
thus allowing applications to communicate with each other through the message
tags (rather than having to know specific device addressing details). Each
bindable message tag requires one address-table space for its exclusive use.
Sending application messages through bindable message tags is also known as
sending application messages with implicit addressing.
Nonbindable message tags enable (and require) the use of explicit addresses,
which the sending application must provide. However, these addresses do not
require address-table space.
Defining a Resource File
Functional profiles, network variable types, and configuration property types are
defined in resource files . L ON W ORKS resource files use a standard format that is
recognized by all interoperable network management tools, such as the
LonMaker Integration Tool. This standard format enables device manufacturers
to create definitions for user functional profiles, user network variable types
(UNVTs), and user configuration property types (UCPTs) that can be used during
installation by a network integrator using any interoperable network
management tool.
A set of standard functional profiles, standard network variable types (SNVTs),
and standard configuration property types (SCPTs) is defined by a standard
resource file set distributed by L
ON M ARK International ( www.lonmark.org ). A
functional profile defined in a resource file is also called a functional profile
template .
Resource files are grouped into resource file sets , where each set applies to a
specified range of program IDs. A complete resource file set consists of a type file
(.TYP extension), a functional profile definitions file (.FPT extension), a format
file (.FMT extension), and one or more language files (.ENG, .ENU, or other
extensions).
Each set defines functional profiles, network variable types, and configuration
properties for a particular type of device. The program ID range is determined by
a program ID template in the file, and a scope value for the resource file set. The
scope value specifies which fields of the program ID template are used to match