L
ON
W
ORKS
I
NTERFACE
M
ODULE
2
O
PEN
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ET
C
ONTROLLER
L
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W
ORKS
I
NTERFACE
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ODULE
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SER
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S
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ANUAL
L
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Network Components
Physical Layer — Transceiver
The L
ON
W
ORKS
interface module incorporates an FTT-10A (Free Topology Twisted Pair Transceiver) for the physical
layer. The FTT-10A transceiver is a transformer-isolated type and has the following specifications:
Note:
The transmission distance is the value when Level 4 AWG22 cables and proper terminators are used.
LonTalk Protocol
The LonTalk protocol has all seven layers in compliance with the reference model of the Open System Interconnection
(OSI) issued by the International Standard Organization (ISO).
Neuron Chip
Some special LSI Neuron Chips that support the LonTalk protocol have firmware embedded in the built-in memory. The
Neuron Chip used in the L
ON
W
ORKS
interface module is Toshiba TMP3150B1AF, with firmware embedded in the exter-
nal memory (flash memory). This Neuron Chip uses a 10MHz quartz clock oscillator. The Neuron Chip and peripheral cir-
cuit are powered through the CPU bus.
Application Program
The application program for the L
ON
W
ORKS
interface module is in compliance with the application layer of the OSI refer-
ence model, and is described in Neuron C that is derived from ANSI C.
Communication data is transferred through the registers located between the
OpenNet Controller
CPU bus and the Neuron
Chip external memory expansion bus. An application program including access to the registers is created and embedded in
the external memory (flash memory) along with firmware by IDEC before shipment. Users do not have to create and
install application programs, although programmers familiar with Neuron C can also create or modify the application pro-
gram using a special tool, such as LonBuilder Developer’s Kit. When a user creates or modifies the application program,
the user must keep a backup file. For application program examples, see pages 18 through 22.
Network Variables
The LonTalk protocol allocates communication data to network variables (NV) specifically designed to simplify the proce-
dures for packet transmission. The variables are available in input network variables and output network variables. The
values of output network variables are transmitted to input network variables of the target node on the network. Details are
described on pages 9 and 23.
Network Management
When setting up a L
ON
W
ORKS
network system, the user has to install network configuration information shown below.
Addressing:
Determines each node address
Binding:
Determines target nodes to communicate with
Configuration:
Determines the type of message service, retry cycles, timeout period, etc.
Use a network management tool from other manufacturers (such as LonMaker for Windows Integration Tool) to install
network configuration information. An external interface file (XIF extension) unique to each product series is needed to
install the network configuration information. The external interface file for the L
ON
W
ORKS
interface module is available
from IDEC. The user must keep a backup file of the information used for network management.
Name
Communication
Media
Transmission
Rate
Transmission Distance
Topology
FTT-10A Transceiver
Twisted pair cable
78 kbps
500m (maximum total wire length)
400m (maximum node-to-node distance)
Free
1,150m
Bus
