Rockwell Automation 1756-DH485 ControlLogix DH-485 Communication Module User Manual - Manual (Page 17)

Publication 1756-UM532A-EN-P - May 2006
1756-DH485 Module Overview 1-9
Alphanumeric Indicators
When you apply power to the module, the alphanumeric display begins to
cycle through the following sequence.
1. All LEDs flash on then off -CHA, CHB OK
2. OK displays red then changes to green.
3. INIT displays.
4. Firmware Revision flashes on scrolling display: DH-485
5. Channel A and the network used for channel A.
6. Channel A node address.
7. Channel A status.
8. Channel B and the network used for channel.
9. Channel B node address.
10. Channel B status.
This sequence runs continuously during normal module operation.
Refer to Appendix B, Troubleshoot the 1756-DH485 Module and publication
1756-IN587, the ControlLogix DH-485 Communications Module Installation
Instructions, for more information about LEDs and status indicators.
EXAMPLE
For example, if your module uses the following:
• Channel A for DH-485 with node address 14
• Channel B is not connected
and the channels are operating properly, you see the
following sequence:
A DH, A#14, A OK, B DH, B#00, ONLY NODE