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Using the LED Indicators and Display for Troubleshooting Section 14-2
Ethernet Information Tab 
Page The Ethernet Information Tab Page shows the communications status at the
communications driver level. The error counter information can be used to
confirm whether communications problems have occurred. The tag data link
information can be used to confirm characteristics such as the bandwidth
usage (pps).
14-2 Using the LED Indicators and Display for Troubleshooting
14-2-1 Errors Occurring at the EtherNet/IP Unit or Built-in EtherNet/IP 
Port
Errors Related to CPU Unit 
Data Exchange The 7-segment display alternates between the node address and error code.
Indicator Error Cause Unit operation (Flag 
status) Error 
log
(hex)
Countermeasure
MS NS 7-segment
Flashing 
red Not lit H1 Duplicate unit 
number The same unit 
number is set on 
another Unit.
Operation stops. --- Set the unit num-
bers correctly and 
restart the Ether-
Net/IP Unit or built-
in EtherNet/IP port.
Flashing 
red Not lit H2 CPU Unit 
faulty --- Operation stops. --- Replace the CPU 
Unit if the error 
recurs when the 
CPU Unit is 
restarted.