Echelon LonTal Stack - Manual (Page 15)

LonTalk Stack Developer’s Guide 3
600 IP-852 Routers, and the LonTalk Stack. This document refers to the
ISO/IEC 14908-1 Control Network Protocol as the LonTalk protocol, although
other interoperable implementations exist.
A L ON W ORKS Device with a Single Processor Chip
A basic L ON W ORKS device consists of four primary components:
1. An application processor that implements the application layer, or both
the application and presentation layers, of the LonTalk protocol.
2. A protocol engine that implements layers 2 through 5 (or 2 through 7) of
the LonTalk protocol.
3. A network transceiver that provides the physical interface for the
L ON W ORKS network communications media, and implements the physical
layer of the LonTalk protocol.
4. Circuitry to implement the device I/O.
These components can be combined in a physical device. For example, an
Echelon Smart Transceiver product can be used as a single-chip solution that
combines all four components in a single chip. When used in this way, the
Echelon Smart Transceiver runs the device’s application, implements the
LonTalk protocol, and interfaces with the physical communications media
through a transformer. The following figure shows the seven-layer LonTalk
protocol on a single Neuron Chip or Echelon Smart Transceiver.
Physical layer
Data link layer
Network layer
Transport layer
Session layer
Presentation layer
Application layer
Transceiver and
wiring
Neuron C
Application
(NodeBuilder FX,
Mini Kit)
Traditional single-chip approach
(Neuron Chip or Smart Transceiver)
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