Digi XBee DigiMesh 2.4, Руководство пользователя

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Work with networked devices Establish and maintain network links
XBee/XBee-PRO DigiMesh 2.4 RF Module User Guide 39
The device that sends a remote command does not receive a remote command response frame if:
1. It could not reach the destination device.
2. You set the frame ID to 0 in the remote command request.
Establish and maintain network links
Build aggregate routes
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 issue 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 frame - 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.
DigiMesh routing examples
Example one:
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.
1. Deploy all devices in the network with the default DH / DL of 0xFFFF.
2. Serially, send an ATAGFFFF command to the aggregator node so it sends the broadcast
transmission to the rest of the nodes.
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.
Example two:
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: