A DTM instance can offer command functions. These functions do not have a user interface, they can have arguments and optional default values.

Each command function shall be mapped to a method in the MethodSet of the device instance (see Figure 15). The arguments are mapped to the InputArguments and OutputArguments for the methods. Optional arguments shall be included.

image019.png

Figure 15 – Example for source of function information

Table 65 – Method node information mapping

OPC

FDT

Attribute

Interface

Method

Data member

Description

BrowseName

IFunctions

FunctionInfo

FunctionItem.Label

DisplayName

IFunctions

FunctionInfo

FunctionItem.Label

Description

IFunctions

FunctionInfo

FunctionItem.Descriptor

The DTMInfoBuilder can offer information about static functions that are independent of a DTM instance. Such FDT Static Functions may be mapped to methods on the device type created for the DTM. The execution of the method on a device object will need to be mapped to the execution of a static function with a StaticFunctionProvider. The Frame/Server will need to hold the reference to the provider internally and use it for execution of the method (see Figure 16).

image020.png

Figure 16 – Example for source of static function information

Table 66 – Method node information mapping for Static Function

OPC

FDT

Attribute

Interface

Method

Data member

Description

BrowseName

IStaticFunctionInformation

GetStaticFunctions

StaticFunctionDescription.Label

DisplayName

IStaticFunctionInformation

GetStaticFunctions

StaticFunctionDescription.Label

Description

IStaticFunctionInformation

GetStaticFunctions

StaticFunctionDescription.Descriptor