36 Rockwell Automation Publication 1783-UM001B-EN-P - May 2010
Chapter 3 Diagnostics
Counters are displayed in hex, where an octet equals 8 bits. TX counters include
the following:
• Tx Octet Count -Total of transmitted good octets from the selected port
• Tx Drop Pkts Count - Packet is not acknowledged by the receiving host
• Tx BroadcastPkts Count - Number of good packets sent with destination
of everyone. Receivers are unspecified
• Tx MulticastPkts Count - Packets sent to members of multicast group. One
terminal to many host
• Tx UnicastPkts Count - In contrast with multicast, consist of one terminal
transmitting to one host
• Tx Collisions Count - Two terminals transmit packets at the same time
causing them to collide. Collision Count should be very low. Collisions
could indicate a faulty device on the network
• Tx SingleCollision Count - Packet collides with one other terminal’s
transmitted packet
• Tx MultipleCollision Count - Packet collides with more than one
terminal’s transmitted packets
• Tx DeferredTransmit Count - Number of packets delayed because the
network is busy (the higher the number the less deterministic your
network)
• Tx LateCollision Count - Collision is detected later than the 512 bits into
the packet transmittion
• Tx ExcessiveCollision Count - Packets not transmitted because the packet
experienced 16 failed attempts
• Tx FrameInDisc Count - Network device is not acting in compliance with
a flow control request
• Tx PausePkts Count - Pause frames sent by this port
RX counters include the following:
• Rx Octets - Total good octets received on selected port
• Rx Undersize Pkts - Good packets that are under 64 octets long
• Rx Pause Pkts - Pause packets received by this port
• Pkts64 Octets - Data packets = 512 bits
• Pkts65to127 Octets - Data packets = 520…1016 bits
• Pkts128to255 Octet - Data packets = 1024…2040 bits
• Pkts256to511 Octet - Data packets = 2048…4088 bits
• Pkts512to1023 Octet - Data packets = 4096…8184 bits
• Pkts1024to1522 Octet - Data packets = 8192…12,176 bits
• RxOversize Pkts - Packets over 12,176 bits or 1523…1536 Octets
• RxJabbers Pkts - Packets longer than 1522 octets and have an error, usually
caused by a faulty device
• RxAlignment Errors - Packets between 64 and 1522 octets and have an
error