User Manual

L.R. Nelson Corporation
One Sprinkler Lane
Peoria, IL 61615
OEM Manual
8602 Radio Module
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CMD
1-byte
SIZE
1-byte
!SIZE
1-byte
DATA
SIZE-bytes
CHK
1-byte
hosts, thus breaking the connection.
Each application side is responsible for
time-out triggers in the case of connection packet failing to reach its destination.
There are essentially two layers in the protocol stack to define operation from
end-end. They are: physical layer and the data-link layer (Nelson Protocol.)
1. PHY Layer, describes the RF layer, frame format and timing
information
2. DL Layer describes the TTL frame protocol between the radio module
and the host.
The first section describes the data link layer (DLL) which internally has been
defined as the Nelson protocol. Following this is a technical description of the RF
layer dictated by the Nelson 8602 radio design.
DATA-LINK LAYER (DLL or Nelson Protocol)
All packets, whether they are local or pass-through, are formatted as shown in
Figure 2. Local packets are for communication between the host and the radio
module for configuration. Pass-through packets are sent from end-end once a
connection is established.
Figure 2: Packet Format – Pass through and local
Packet format decoding is described below. SIZE dictates the DATA payload size
whereby !SIZE is the binary inversion of SIZE. CHK is the modulo 256 checksum
of all bytes preceding it. Using the SIZE value and the CHK byte for verification
allows for frame delimiting.