Rockwell Automation 1756-DHRIO_DHRIOXT ControlLogix Data Highway Plus-Remote I/O Communication Interface Module - Manual (Page 156)

156 Rockwell Automation Publication 1756-UM514C-EN-P - June 2014
Chapter 13 Troubleshooting the Module
Minimizing False Received
Frame with Bad CRC
Messages 1756-DHRIO and 1756-DHRIOXT modules that communicate with a
1784-KT or 1784-PCMK communication card on their DH+ link can receive
the following error message:
Received Frame with Bad CRC
This error does not affect DH+ link operations. To minimize its occurrence,
make sure that the DH+ link is terminated properly.
Channel Status - Channel A and Channel B Indicators
If the Channel A
or B
indicator is: In this channel
mode: Channel status is: Take this action:
Off All Not online. Place channel online.
Green RIO scanner Active RIO link. All adapter
modules are present and not
faulted. None, normal operation
DH+ Operating. None, normal operation.
Green flashing RIO scanner One or more nodes faulted or
failed. Check power at other racks.
DH+ No other node on the network. Check cables.
Red All Hardware fault. Restart module. If red still on, replace
module.
Red flashing RIO scanner Faulted adapters detected. Check cables. Check power at other
racks.
DH+ Duplicate node detected. Check node address.