The interface connects any ([C] or [N]) network device to the external autonomous device and allows the external device to control the network and/or network device. By default the interface is always enabled at [C] device because it gives an external device means to control the [C] as well as the rest of the network. The interface at [N] device is enabled if the appropriate DPA plug-in is uploaded. See DPA Messages for details of the messages exchanged over the interface. Next table shows some differences in the interface behavior at different network devices:
|
Topic |
Device |
|
|
[C] |
[N] |
|
|
DPA Messages |
DPA
Request (in) |
DPA
Request (in) |
|
NADR at DPA Request |
See NADR at General message parameters. Invalid value generates an ERROR_NADR error code. Both values 0x0000 and 0x00FC address the [C] device itself. |
Only value 0x00FC is allowed and it addresses the [N] device itself. Other values are silently ignored. There is no way to directly control [C] device coupled to [N] by its interface. |
See Examples of interface usage.