Echelon OpenLNS Commissioning Tool - Manual (Page 196)

180 Monitoring and Controlling Networks
The format may include scaling and offset values to convert one type of data to another such as Celsius
to Fahrenheit or kilograms to pounds, localized formatting specifications, or text strings that are to be
displayed as part of the value. For example, a temperature sensor may report a temperature value with
a type of SNVT_temp_f. The SNVT_temp_f type is defined as a 32-bit signed floating-point value
representing a Celsius temperature. You can change the format of SNVT_temp_f type to Fahrenheit
or differential Fahrenheit (the Fahrenheit format has an offset of 32; differential Fahrenheit has an
offset of 0). You can modify network variable and configuration property formats or create your own
using the NodeBuilder Resource Editor.
If you change a network variable type, the format is automatically changed to the default format for the
new type. You can change the format to a format associated with a different type than the actual
network variable type. For example, a network variable may have a fixed type of SNVT_count_f, but
you may set its format to SNVT_temp_f#SI to interpret the count value as a Celsius temperature.
A network variable or configuration property format does not affect how the corresponding value is
encoded for transmission on the network. For example, a SNVT_temp_f value is always transmitted
in Celsius format, but it can appear in Celsius, Fahrenheit, or differential Fahrenheit formats.
You can use the OpenLNS CT Browser to change the format of network variables and configuration
properties. To do this, right-click the network variable or configuration property in the browser
window and then click Change Format on the shortcut menu. The Select Network Variable Format
dialog opens.
This dialog lists available types and formats. Each format is associated with a type. If a type supports
multiple formats, you can expand the type to see all the associated formats. By default, the dialog
opens to the current type with its formats listed underneath it (if it has more than one) and the current
format highlighted.
To change the format, click the desired format and then click OK. In addition to the formats contained
in the standard format file and other format files included in this dialog, you may choose to format the
data in one of five built-in data types: RAW, RAW_HEX, RAW_PACKED, STRING, or
UNIT_TEXT. To choose one of these formats, expand the Built-in Data Types header and select the
desired format.
• Select the Show Only Types with Matching Length check box to list only those network
variable types with the same size as the current SNVT, UNVT, or built-in data type.