IQMESH network is controlled by the DPA protocol from a control system connected to the Coordinator via the SPI or UART interface. The communication in IQMESH is primarily intended as the synchronous one: Request – Response.
● For the first familiarization with DPA communication, using a TR transceiver plugged in the CK-USB-04A kit with IQRF IDE as a control system is recommended.
● In real applications, the control system is usually integrated with the host of the Coordinator into single equipment (gateway), often linked up to additional high-level services.
DPA communication is possible:
● Locally – with the Coordinator (by wires)
• The control system sends a DPA Request to the Coordinator
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● Remotely – with a Node in the network (through the Coordinator, wirelessly)
• The control system sends a DPA Request to the given Node
• The Coordinator returns a DPA Confirmation.
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Refer to the IQRF DPA Framework Technical guide, chapter DPA Messages.
4 packet types are possible:
● Unicast
DPA Request is intended for one particular network device.
• With address 1 to 239, intended for one Node
• With address 0, intended for the Coordinator
The addressed Node or Coordinator always sends a DPA Response.
● Broadcast
DPA request with address 255 is intended to all Nodes (or a group on Nodes with specified HWPID).
No DPA response is sent.
DPA Request intended to all Nodes or a group of Nodes.
Individual responses are collected by all Nodes and delivered to the Coordinator. Additionally, another type of FRC (so-called Local FRC) enables FRC sending from a Node to other Nodes in the direct RF range.
● Beaming
A special type of packet asynchronously sent from a Beaming sensor to all Aggregating repeaters in the direct RF range, to be subsequently synchronously forwarded to the Coordinator by Offline FRC.