NetDecoder gathers and maintains important statistical information related to the network being monitored. This information is crucial to debug and troubleshoot communication problems on the industrial network.

The Statistics display window includes information that is relevant for all networks. This information includes:

  • Bandwidth Utilization data.
  • Frame rate (Frames/second).
  • Character or Byte rate (bytes/second).
  • Frame/message size distributions.
  • Error information.

Apart from the above common information, NetDecoder also gathers data specific to the properties of the industrial network being monitored. Some examples of this include statistics for Ethernet, ControlNet, DeviceNet and DH+.

Ethernet Statistics

The statistics dialog for the Ethernet analyzer includes error information supported by the NDIS drivers. Since not all errors are supported by all NDIS drivers, the ones not supported are marked "n/a". Some of the Ethernet errors statistics reported include:

  • Ethernet StatisticsCRC errors.
  • Alignment errors.
  • Number of received frames with errors.
  • Number of transmitted frames with errors.
  • Number of frames successfully transmitted after detecting one collision.
  • Number of frames successfully transmitted after detecting multiple collisions.
  • Number of frames successfully transmitted after transmission has been deferred at least once.
  • Number of frames not transmitted due to excessive collisions.
  • Number of frames not transmitted due to under-run errors.
  • Number of frames transmitted without detecting the collision detection heartbeat.
  • Number of times carrier sense was lost during frame transmission.
  • Number of collisions detected after the normal window.

To learn more about troubleshooting Ethernet networks, download a NetDecoder demo. You can also order your copy of NetDecoder online.

ControlNet Statistics

ControlNet U2CN Statistics NetDecoder's ControlNet analyzer uses the 1784-U2CN or the 1784-PCC card as the sniffer interface. The interface cards are designed around the ControlNet CNA10 ASIC. The ControlNet analyzer gathers information about frames dropped by the CNA10 ASIC. The protocol analyzer also provides the number of frames that were dropped by the buffer in the 1784-U2CN device. Other useful ControlNet related error information includes the number of bad frames received and the MAC IDs of nodes transmitting bad frames. The ControlNet analyzer maintains a list of the last eight MAC IDs that transmitted bad frames.

DeviceNet Statistics

DeviceNet U2DN Statistics NetDecoder supports two options for running the DeviceNet analyzer. Users can choose either Rockwell Automation's 1784-U2DN or SST's DeviceNet interface cards. For both these interfaces, NetDecoder provides statistics on

  • CRC errors.
  • Bit-stuff errors and error flags.
  • Firmware buffer overflows (U2DN or SST interface).
  • Frame errors.


To learn more about troubleshooting ControlNet or DeviceNet networks, download a NetDecoder demo. You can also order your copy of NetDecoder online.

DH+ Statistics

NetDecoder's DataHighway-Plus analyzer includes a special "Dashboard View". This presents statistics on:

  • Data Highway Plus Dashboard StatisticsBusy tokens.
  • Total bytes sent.
  • Event log.
  • Token rotations.
  • Top listeners.
  • Top talkers.
  • Top conversations.

Another unique feature of NetDecoder's Statistics display is multiple tabs on the Statistics dialog. All the screenshots above show three tabs in the dialog. These tabs are named "Session", "Resettable" and "Capture File".

Information about all data collected since the analyzer was started is shown in the Session tab. The Session tab cannot be reset; in this sense, it is like the odometer on a car. The odometer on a car shows you all the miles driven since the car was built, and the Session tab shows you all the data collected since the analyzer was started.

If you think of the Session tab as the odometer, then the Resettable tab is the trip odometer. It can be reset, and allows you to record statistics for a new "trip". In this way you can effectively start a new session without having to restart the analyzer.

The Capture File tab shows information on the data that is currently in the capture. Occasionally some of the statistics read n/a, for Not Available. This happens for various reasons. For example, many of the items on the Capture File tab become not available (n/a) if the buffer becomes full and wraps. When this happens, the analyzer can no longer provide accurate statistics for the data in the file, because some of the data that the statistics are based on has been lost.

To learn more about diagnosing and troubleshooting industrial networks order your copy of NetDecoder online.