Acknowledged Rf Mode; Addressing; Address Recognition; Basic Communications - Digi XTend User Manual

Acknowledged RF mode

Acknowledged.

Addressing

Each RF packet contains addressing information that the receiving devices use to filter incoming RF data. Receiving
devices inspect the Preamble ID (HP parameter), Vendor Identification Number (ID parameter) and Destination
Address (DT parameter) in each RF packet. A receiving device discards all data that does not pass through all three
network security layers.
The following image illustrates the addressing layers in the RF packet header.

Address recognition

The transmitting device can address transmissions to a specific device or group of devices using the DT and MK
commands. A receiving device only accepts a packet if it determines that the packet is addressed to it, either as a
global or local packet. The receiving device makes this determination by inspecting the destination address of the
packet and comparing it to its own address and address mask.
The transmitting device determines whether the packet is for a specific node (local address) or multiple nodes (global
address) by comparing the packet's destination address (DT) and its own address mask (MK). This assumes you
program the address masks on the transmitting device and receiving device to the same value for proper operation in
each RF communication mode.
For more information, see the DT (Destination Address and MK (Address Mask) commands.

Basic communications

Basic communications includes two sub-types:
•
Broadcast. By default, the XTend RF Module communicates through Broadcast communications and within a
peer-to-peer network topology. When any device transmits, all other devices within range receive the data and
pass it directly to their host device.
•
Addressed. If addressing parameters match, the device forwards the RF data it receives to the DOUT buffer;
otherwise, it discards the RF data.
When using Basic communications, the integrator handles any functions, such as acknowledgments, at the
application layer. The Broadcast modes provide transparent communications, meaning that the RF link replaces a
wired link.
XTend RF Module User Guide
Addressing
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