Connect Modes#

Connect supports three distinct modes of operation. Only one mode is allowed in any single network and there is no simple way to upgrade from one mode to the other. As a result, you should select the mode carefully early in the design process.

Extended Star Mode#

In this mode, Connect supports extended star topology networks as illustrated in the following figure.

Data message routing between any two devices is supported by the network layer in this mode. End devices can be configured to be sleepy, which means they do not keep their radio in receive when idle. The network layer also provides endpoints for messages which are set by the sender and seen by the receiver and can be used similarly to a TCP/IP port.

Extended star topology is a centralized network. Joining to it must be accepted by the PAN coordinator and short address allocation can be handled by the PAN coordinator.

This mode is not fully IEEE 802.15.4 compliant.

Direct Mode#

In this mode, Connect only provides connections between devices that are in range of each other as illustrated in the following figure.

The Connect network layer is still enabled in this mode, but it does not provide routing, only endpoints. However, routing protocols can be implemented in the application layer.

This is not a centralized topology. Any device can join the PAN by setting the right PAN parameters. Short address allocation is not provided by the stack and address duplication must be avoided by the application.

This mode is not fully IEEE 802.15.4 compliant.

MAC Mode#

MAC mode is a fully IEEE 802.15.4 compliant setup of the Connect MAC layer. The Connect network layer is not enabled, which renders some components unusable in this mode (because some components require endpoints). The API is more complex compared to Direct mode and requires some knowledge of the IEEE 802.15.4 standard.

To make it fully IEEE 802.15.4 compliant, make sure to set up a 15.4-compliant radio configuration.