Echelon LNS DDE Server - Manual (Page 114)

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Resource Files
The LNS DDE Server supports L ON M ARK resource files that define standard and
user-defined network variable types, configuration property types, and functional
profile templates (definitions of L ON M ARK object types). The LNS DDE Server is
compatible with resource files that comply with version 3.2 of the LonMark
Application Layer Interoperability Guidelines.
Standard network variable types (SNVTs) and standard configuration property
types (SCPTs) are defined in the STANDARD.TYP file. Standard functional profile
templates are defined in the STANDARD.FPT file. These standard types are
defined by the L ON M ARK Interoperability Association. Formatting instructions
for the standard types are defined in the STANDARD.FMT file. These files are
updated periodically as the L ON M ARK Interoperability Association defines new
standard types. The latest version of the standard resource files is available on
the L ON M ARK website at http://www.lonmark.org/products/guides.htm under
SNVT and SCPT.
Resource files also include language-dependent string files. The filename
extension of the string file depends on the language being used. For example,
the US English string file is named STANDARD.ENU and the UK English string
file is named STANDARD.ENG.
In addition to the standard resource files, there may be multiple sets of user-
defined resource files. (See the Device Resource File help file for more
information about user-defined resource files.) These files are keyed by
components of the program ID, using standard formats 8 (L ON M ARK certified
device) and 9 (L ON M ARK compliant device). Since there may be many user-
defined resource files, a standard resource catalog is used to manage and
organize the resource files. This resource catalog may be modified using the LNS
Resource File Catalog Utility. The resource catalog also may be updated
automatically by a device manufacturer’s software installation program. See the
LNS Resource File Catalog Utility User's Guide under the LonMark Reference
topic in the LNS Utilities and LonMark Reference help file for more information.
A shortcut to this help file is in the Echelon LNS Utilities program folder on the
Windows Start menu. Additional tools for developing resource files are available
in the update area at www.echelon.com/lonmaker.
The following sections describe the file types.
Type File
The type files (e.g. STANDARD.TYP) contain information about network variable
types (NVTs), enumeration types, and configuration property types (CPTs).
The LNS DDE Server uses the information in the type files in conjunction with
the information in the format files to convert raw data to a scaled and formatted
display, and to convert formatted data back to raw data. For example, a time-of-
day reading can be converted to hours, minutes, and seconds. One or more sets
of user type and format files can be used for conversion of additional, non-
standard types. These sets of user type and format files are selected by matching
with various parts of the program ID of the device containing the data being
accessed by the LNS DDE Server.
A-2 Resource Files