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
B-2 Troubleshoot the 1756-DH485 Module
If the alphanumeric indicator on the 1756-DH485 module does not cycle
through these messages when you apply power, refer to the following table and
to the troubleshooting section that follows.
Power Cycle Indicators
Interpret the LED Status
Indicators
The LED status indicators on the module provide information about your
module and the status of each channel. The following tables outline the
indicator condition and the corresponding status, and explain what each
condition means.
Interpret the LED Status Indicators
If the POWER
Indicator is
Power Supply
Status is
Recommended Action
Off Not operating. Turn power ON.
Check power wiring connections.
Check fuse.
On Operating. None, normal operation.
Module OK
Indicator
Module Status Recommended Action
Off Not operating. Apply chassis power.
Verify module is completely inserted into
chassis and backplane.
Green flashing Operating but not
routing messages.
None, if no messages are actively being
routed through the module.
To route messages, configure module with
RSLinx software.
Solid Red, then Off Performing self-test. None, normal operation.
Solid Green Operating and routing
messages.
Verify module configuration.
Solid Red In major fault. Reboot module. If red reoccurs, then
replace module.
Red flashing In major fault or
configuration fault.
Check alphanumeric indicator and take
action described in the Alphanumeric
Display Descriptions table.