3.1 Device Details

The device is the stub waiting to receive service messages. Upon receiving the service messages it processes them and returns the responses to the proxy.

The Device Session Property Access Protocol device has the following states, as illustrated in the following figure:

  1. Start

  2. Accepting request

  3. Processing request

  4. Finish

Device state machine

Figure 2: Device state machine

Start State

The device is ready to instantiate services. The following message is processed in this state:

  • CreateService

Accepting Messages

The device has received the CreateService message to instantiate the service, and is ready to accept requests on that service. The following events are processed in this state:

  • Two-way request

  • DeleteService

Processing Request

The device is executing a two-way request received from the host, including sending the response for two-way requests. The following event is processed in this state:

  • Two-way response

Finish State

The device has received the DeleteService message and cleaned up the remote service. No events are processed in this state.