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 200 6
Overview of the DH-485 Network 2-11
Plan Cable Routes
Follow these guidelines to help protect the communication cable from
electrical interference:
• Keep the communication cable at least 1.52 m (5 ft) from any electric
motors, transformers, rectifiers, generators, arc welders, induction
furnaces, or sources of microwave radiation.
• If you must run the cable across power feed lines, run the cable at right
angles to the lines.
• If you do not run the cable through a contiguous metallic wireway or
conduit, keep the communication cable at least 0.15 m (6 in.) from ac
power lines of less than 20A, 0.30 m (1 ft) from lines greater than 20A,
but only up to 100k VA, and 0.60 m (2 ft) from lines of 100k VA or
more.
• If you run the cable through a contiguous metallic wireway or conduit,
keep the communication cable at least 0.08 m (3 in.) from ac power lines
of less than 20A, 0.15 m (6 in.) from lines greater than 20A, but only up
to 100k VA, and 0.30 m (1 ft) from lines of 100k VA or more.
Running the communication cable through conduit provides extra
protection from physical damage and electrical interference. If you route
the cable through conduit, follow these additional recommendations:
– Use ferromagnetic conduit near critical sources of electrical
interference. You can use aluminum conduit in non-critical areas.
– Use plastic connectors to couple between aluminum and
ferromagnetic conduit. Make an electrical connection around the
plastic connector (use pipe clamps and the heavy gauge wire or wire
braid) to hold both sections at the same potential.
– Ground the entire length of conduit by attaching it to the building
earth ground.
– Do not let the conduit touch the plug on the cable.
– Arrange the cables loosely within the conduit. The conduit should
contain only serial communication cables.
– Install the conduit so that it meets all applicable codes and
environmental specifications.
For more information on planning cable routes, see Industrial Automation
Wiring and Grounding Guidelines, Publication Number 1770-4.1.