12.2.6.1 General
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.

| 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).

| OPC | FDT | |||
|---|---|---|---|---|
| Attribute | Interface | Method | Data member | Description |
| BrowseName | IStaticFunctionInformation | GetStaticFunctions | StaticFunctionDescription.Label | |
| DisplayName | IStaticFunctionInformation | GetStaticFunctions | StaticFunctionDescription.Label | |
| Description | IStaticFunctionInformation | GetStaticFunctions | StaticFunctionDescription.Descriptor | |