User Manual
Table Of Contents
- 1756-UM532A-EN-P
- Important User Information
- Table of Contents
- Purpose of This Manual
- Preface
- 1756-DH485 Module Overview
- Overview of the DH-485 Network
- Introduction
- DH-485 Network Description
- DH-485 Network Protocol
- DH-485 Token Rotation
- DH-485 Network Initialization
- Devices that Use the DH-485 Network
- 1747-AIC Isolated Link Coupler for DH-485
- 1761-NET-AIC Advanced Interface Converter Product Overview
- Operating Modes
- Device Compatibility
- Misconception about the 1761-NET-AIC Converter
- 1747-UIC USB to DH-485 Interface Converter
- Example System Configuration
- Important Planning Considerations
- Additional Resources
- Use Data Highway 485 Network
- Use RSLinx Software to Create a Routing Table
- Communicate from an SLC 5/03 Controller to a Logix Controller over a DH-485 Network
- Communicate Between SLC Controllers over DH+ and DH485 Networks
- Communicate Between a PLC-5 Controller and a Remote SLC 5/03 Controller over Multiple DH-485 Networks
- Communicate from an SLC 5/05 Controller to an SLC 5/03 Controller over an EtherNet/IP Network
- Communicate to a SLC 5/03 Controller on a DH-485 Network
- Communicate from a Logix Controller to an SLC 5/03 Controller over EtherNet/IP and DH-485 Networks
- Specifications
- Troubleshoot the 1756-DH485 Module
- Index
- How Are We Doing?
- Rockwell Automation Support
- Backcover

Publication 1756-UM532A-EN-P - May 2006
4-2 Use RSLinx Software to Create a Routing Table
Use RSLinx Software to
Create a Routing Table
DH-485 protocols do not use the Common Industrial Protocol (CIP), the
communication protocol used in the ControlLogix architecture. The
1756-DH485 module is the transition point from the DH-485 network to
ControlLogix. In this capacity, the 1756-DH485 module serves as the DH-485
message source and requires a full message route, or path, to deliver the
message. A routing table, using link IDs and node addresses, provides the full
path.
What Is a Routing Table?
Before you can create a routing table for your 1756-DH485 module, you must
assign link IDs to all networks (including ENET and CNET) that route
information through the module. Link IDs are numbers from 1 to 199.
DH-485 module addressing provides the link IDs and node addresses. The
routing table translates link IDs and node address information into path, or
routing, information. Thus, the routing table specifies a 'map' to other links in
the system. Routing tables are set up at each node to build accurate
connections.
ControlLogix Routing
The ControlLogix routing protocols use CIP, a message-based protocol that
implements a relative path to send a message from the source device in a
system to the destination device. In this way, the source device in a networks
system contains the path information that steers the message along the proper
route to reach its destination. Since the source device holds this information,
other devices along the path simply pass this information; they do not need to
store it. ControlLogix routing has two significant benefits:
• You do not need to configure routing tables in the bridging module,
greatly simplifying maintenance and module replacement.
• You maintain full control over the route taken by each message, enabling
you to select alternative paths for the same end device.