Echelon LonTal Stack - Manual (Page 179)

LonTalk Stack Developer’s Guide 167
Use a SNVT or SCPT if one is available that matches your data because
SNVTs and SCPTs can provide interoperability with other devices.
• A user network variable type (UNVT) or user configuration property type
(UCPT) defined in a user resource file. You can use the NodeBuilder
Resource Editor to create custom UNVTs and UCPTs, and to view the
available UNVTs and UCPTs in your resource files. Use a UNVT or
UCPT if you cannot find an appropriate SNVT or SCPT for your data.
• Any of the following built-in types (including single-dimension arrays,
unions, structures, or named types of the following types):
[signed] long int
unsigned long int
signed char
[unsigned] char
[signed] [short] int
unsigned [short] int
enum (an enum is int type)
In general, built-in types should not be used because they cannot be
verified by network management tools when creating connections.
Network variables based on built-in types are not interoperable.
The Network Variable Connection
Information
The optional connection-info specification for a network variable defines options
in the network variable table and the SI and SD data for a LonTalk Stack
application. If the nonconfig keyword is not specified, these connection
information assignments can be overridden by a network management tool when
a device is installed.
The syntax for the connection-info specification is:
bind_info (
[ expand_array_info ]
[ offline ]
[ unackd | unackd_rpt | ackd [ ( config | nonconfig ) ] ]
[ authenticated | nonauthenticated [ ( config | nonconfig ) ] ]
[ priority | nonpriority [ ( config | nonconfig ) ] ]
[ rate_est ( const-expr ) ]
[ max_rate_est ( const-expr ) ]
)
The following keywords can be specified in any order:
expand_array_info
Includes individual names for each element of an array in the device’s SI and
SD data, and in the device interface file. The names of the array elements
have unique identifying characters postfixed. These identifying characters
are typically the index of the array element. For example, an xyz[4] network
variable array becomes four separate xyz__0, xyz__1, xyz__2, and xyz__3