Additional resources for dh-485 communication – Rockwell Automation 1769-L23E-QB1B_L23E-QBFC1B_L23-QBFC1B CompactLogix Packaged Controllers Quick Start and User Manual User Manual
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Publication IASIMP-QS010B-EN-P - October 2009
Chapter 2 Network Communication
9. Use the table below as a reference to specify the DH-485 settings
specific to your system.
Additional Resources for DH-485 Communication
Rockwell Automation publications are available for electronic download at
or by contacting your distributor.
DH-485 System Protocol Specifications
Characteristic
Description
Station Address
Specifies the node address of the controller on the DH-485 network. Select a number 1...31 decimal,
inclusive.
To optimize network performance, assign node addresses in sequential order. Initiators, such as personal
computers, should be assigned the lowest address numbers to minimize the time required to initialize the
network.
Token Hold Factor
Number of transmissions plus retries that a node holding a token can send onto the data link each time it
receives the token. Enter a value between 1...4. The default is 1.
Maximum Station Address
Specifies the maximum node address of all the devices on the DH-485 network. Select a number 1...31
decimal, inclusive.
To optimize network performance, make sure:
•
the maximum node address is the highest node number being used on the network.
•
that all the devices on the same DH-485 network have the same maximum node address.
Resource
Description
Data Highway/Data Highway
Plus/Data Highway II/Data Highway
485 Cable Installation Instructions,
This manual explains how to install various Data
Highway cable networks, including the DH-485
network.