Reference
MVI56E-FLN ♦ ControlLogix Platform
User Manual
FA Control Network Ethernet Communication Module
Page 98 of 155
ProSoft Technology, Inc.
User-Defined Specifications
User-defined specifications allow the following range of features that are required
for FA systems.
1
Large-scale network
Up to 254 devices (nodes) can be connected in the physical layer of the
network.
"1 through 254" shall be used as node number. However, numbers "250
through 254" are reserved for maintenance purposes. Number "0" shall not
be used.
Number "255" shall be used as the global address for broadcasting.
2
Dual communications functions to suit application
The Common Memory function uses cyclic transmission so that each node
can always share the same data with other nodes on the network. FL-net also
supports message communications for use when handling only essential data
is required.
3
Large-capacity Common Memory
The Common Memory is provided with a large capacity of 8K bits (Area 1)
and 8K words (Area 2).
4
High-speed response
High-speed response time of 50 milliseconds / 32 nodes (for 2K bits and 2K
words) is provided. The absence of a Master in the FL-net network enables
nodes to be added or removed readily without affecting any other nodes. This
allows any node to be turned ON or OFF easily and facilitates maintenance.
The FL-net protocol is characterized by the following items:
1
Transmission control using masterless token system avoids collision.
2
Refresh cycle time can be specified since the system circulates a token in a
fixed time.
3
The token is transmitted together with cyclic data.
4
The node with a smallest node number among those who participate the
network at start-up time shall start to send the token.
5
If no token is transmitted for a specified period, next node in the token
circulation ring shall send a new token.
6
The masterless token system (characterized by the above two items) will
keep the network from stopping in case of failure of some nodes.
7
The protocol provides information management tables for useful information
to refer operation status of other nodes such as operation mode (RUN /
STOP) and hardware malfunction (ALARM).
