User manual

156 Publication ENET-UM001I-EN-P - January 2010
Chapter 11 Troubleshoot an EtherNet/IP Module
2. Review the values in the Media Counters table.
If Then
Any media counters are greater than zero You need to investigate further.
These errors are counted:
· Alignment
· FCS
· Carrier Sense
A duplex mismatch ex
ists between your EtherNet/IP module and the switch port.
To clear the duplex mismatch:
a. Configure the EtherNet/IP module and the corresponding Ethernet switch
port for a forced operation, not autone
gotiation. See Configure the Module
with RSLinx Software on
page 48 .
b. Verify that the firmware revision of your Logix controller and switch or
converter are identical.
c. If the revisions are not identical, replace the controller, switch or converter
so that they match.
Single Collisions
or Multiple Collisions
are greater than zero
No action is required.
Important: If two stations attempt to transm
it data simultaneously, the packets
collide with each other. However, collisions are not errors and do not indicate a
network problem. The number of network collisions can vary greatly due to traffic
patterns or CPU utilization. Consequently, there is no set range of acceptable
collisions for each outgoing packet. Collisions are a normal aspect of Ethernet
networking.
Late Collisions are greater than zero a. Check to see if a network segment is too long.
b. Remove repeaters from between devices.
Excessive Collisions are greater than zero Calculate your network’s typical rate of excessive collisions and decide whether
the rate of packet loss will affect your network’
s
performance.
Important: Excessive collisions indicate that yo
ur network has become
congested. For each collision after the sixteenth, your network drops a packet.
MAC Transit Errors are greater than zero No action is required.
Frame Too Long is greater than zero Limit the size of your tags to ≤ 500 bytes. See Tag Guidelines for Produced or
Consumed Data on
page 95 .