In many applications, many or all of the nodes in the network must transmit data to a central aggregator node. In a new DigiMesh network, the overhead of these nodes discovering routes to the aggregator node can be extensive and taxing on the network. To eliminate this overhead, you can use the AG command to automatically build routes to an aggregate node in a DigiMesh network.
To send a unicast, devices configured for Transparent mode (AP = 0) must set their DH/DL registers to the MAC address of the node that they need to transmit to. In networks of Transparent mode devices that transmit to an aggregator node it is necessary to set every device's DH/DL registers to the MAC address of the aggregator node. This can be a tedious process. A simple and effective method is to use the AG command to set the DH/DL registers of all the nodes in a DigiMesh network to that of the aggregator node.
Upon deploying a DigiMesh network, you can send the AG command on the desired aggregator node to cause all nodes in the network to build routes to the aggregator node. You can optionally use the AG command to automatically update the DH/DL registers to match the MAC address of the aggregator node.
The AG command requires a 64-bit parameter. The parameter indicates the current value of the DH/DL registers on a device; typically you should replace this value with the 64-bit address of the node sending the AG broadcast. However, if you do not want to update the DH/DL of the device receiving the AG broadcast you can use the invalid address of 0xFFFE. The receiving nodes that are configured in API mode output an Aggregator Update API frame (0x8E) if they update their DH/DL address; for a description of the frame, see Aggregate Addressing Update - 0x8E.
All devices that receive an AG broadcast update their routing table information to build a route to the sending device, regardless of whether or not their DH/DL address is updated. The devices use this routing information for future DigiMesh unicast transmissions.
In a scenario where you deploy a network, and then you want to update the DH and DL registers of all the devices in the network so that they use the MAC address of the aggregator node, which has the MAC address 0x0013A200 4052C507, you could use the following technique.
All the nodes in the network that receive the AG broadcast set their DH to 0x0013A200 and their DL to 0x4052C507. These nodes automatically build a route to the aggregator node.
If you want all of the nodes in the network to build routes to an aggregator node with a MAC address of 0x0013A200 4052C507 without affecting the DH and DL registers of any nodes in the network:
You can use the AG command to update the routing table and DH/DL registers in the network after you replace a device. To update only the routing table information without affecting the DH and DL registers, use the process in example two, above.
To update the DH and DL registers of the network, use example three, below.
This example shows how to cause all devices to update their DH and DL registers to the MAC address of the sending device. In this case, assume you are using a device with a serial number of 0x0013A200 4052C507 as a network aggregator, and the sending device has a MAC address of 0x0013A200 F5E4D3B2 To update the DH and DL registers to the sending device's MAC address: