EC-Inspector: Troubleshooting and Monitoring Tool for EtherCAT® Networks


EC-Inspector is an easy to use software application for Windows for analyzing and monitoring EtherCAT networks. The program can be used independently of the master controller and works with EtherCAT masters from many manufacturer (Beckhoff, Omron, Bosch-Rexroth, Lenze, acontis, etc.). EC-Inspector analyzes the complete data traffic between the master and the EtherCAT slaves via a TAP (Test Access Point) device inserted after the master. The TAP device enables both the outgoing frames (Master → Slaves) and the incoming frames (Master ← Slaves) to be recorded and evaluated.

EtherCAT Analysis Without Any Impact on the Network

With EC-Inspector, there is no need to intervene in the network, control, the EtherCAT master software, or the configuration. EC-Inspector is therefore suitable for new installations (greenfield) as well as for existing systems and machines (brownfield). The raw data (EtherCAT frames) is decoded and associated with the corresponding symbolic variables (inputs and outputs) based on the descriptions from the EtherCAT Network Information file (ENI).

In addition to monitoring process data, EC-Inspector can also be used to analyze communication faults on the EtherCAT network. As long as the EtherCAT master software is regularly checking the slave error counter register, this data can also be analyzed by EC-Inspector and the faults can be clearly visualized in the topology view.


System Architecture

A Test Access Point (TAP) must be inserted into the existing EtherCAT network to capture the EtherCAT frames. The TAP is recommended to be placed between the master and the first slave, but it can also be installed between any two slave devices. However, it is only possible to completely analyze all input and output data when the TAP is installed immediately after the master, because some data (LRW commands) are overwritten by the downstream slave's subsequent input data. The TAP device selected, e.g. Dualcomm ETAP-1000, should have a small propagation delay to as to not disturb the overall network timing.

The "monitor" port of the TAP is connected to the computer running EC-Inspector via a standard Ethernet cable.

Analyzing and Decoding of EtherCAT Protocol based on network configuration file (ENI)

The recorded EtherCAT frames are decoded based on what is included in the EtherCAT Network Information (ENI) file. This file contains the definition of the process image, all variables including the data types, as well as the structure of the cyclic frames. The ENI file is part of the EtherCAT specification ETG.2100 and can be generated by any EtherCAT configuration software.

Monitoring of Process Data Variables

One of the core functions of EC-Inspector is to display the process data (inputs and outputs) in a live chart. The last 500 values of each variable are shown in the chart over time, and the user can adjust if they want to see more or less values. A zoom function allows a certain section to be viewed, including the ability to determine the exact values. The relevant data for monitoring can also be organized into a watch list for faster access to the pertinent data.

The continuous display can be stopped manually or automatically by programmable trigger conditions. A trigger condition can compare a certain variable (input or output) with a fixed value or with another variable. Various comparison operators are available for the trigger conditions. After a trigger has been hit, the other variables and other related data (slave states, error counters, etc.) can be analyzed.

Monitoring of Slave State

The status of the individual slaves can be identified quickly and easily in the topology view using a clear color coding (Init = white, PreOp = blue, SafeOp = yellow, Op = green).

Analysis of Communication Problems Frame Errors, Link Loss, etc.

Part of the data communication recorded by the EC-Inspector contains information that informs about the transmission quality of the network. EC-Inspector processes this information accordingly and displays the results graphically.

For example, the location and cause of possible errors can be determined from the slave and port-specific error counters (bad cables or faulty plug connections). In the topology view, this is indicated by corresponding symbols. In addition, every new error that occurs is also reported and logged.

Capturing and Processing of network traffic (Wireshark file)

EC-Inspector makes it possible to monitor live data and save the complete traffic to a PCAP file (in parallel). This file can also be loaded and evaluated with EC-Inspector to analyze process data and errors cycle by cycle. This feature provides a simple and fast detection of communication faults, as well as a symbolic association of all input and output data. The investigation of PCAP files recorded by Wireshark is also possible.

After loading the PCAP file, it can be evaluated in various adjustable speeds or in individual steps (cycle by cycle). The operation within EC-Inspector is similar to an oscilloscope, whose input signals (according to the sample of the oscilloscope) are determined from the PCAP file. For example, a certain process data variable can be selected here, then EC inspector shows the temporal progression of the signal as it results from the PCAP data.

When a slave changes state (e.g. from OPERATIONAL to SAFEOP), a log entry with a time stamp is created in the message window. For example, the exact time of an error can be determined.

Corresponding trigger and search functions make it possible to stop processing (recording) in a targeted manner for a specific situation or when an error is detected. For example, a stop can be made when a certain variable value is reached, or when a slave leaves the operational state.

With EC-Inspector a powerful graphical Wireshark oscilloscope (debugger) is available!

Snapshot and Offline Diagnosis

  • Collect data from the current diagnosis state and save it into a capture file
  • Offline investigation mode for analyzing captured data
  • Capture file can be emailed for further analysis by someone else
  • Use captured data as documentation, like for a status report


  • Analyzing and Decoding the EtherCAT Protocol
  • Utilizes the EtherCAT Network Information (ENI) file
  • Monitoring of Process Data Variables including Trigger Conditions
  • Monitoring of Slave States
  • Monitoring of Slave Error Counters (ESC registers 0x300 to 0x313)
  • Graphical View of Network Topology
  • Processing of Previously Captured and Saved Raw Network Traffic (Wireshark files)
  • Take Snapshots to Save to Files


  • No integration with the existing master controller required
  • No specific TAP device required, even a regular switch device may be used
  • No impact (e.g. timing, load) on the existing network and application
  • No changes to existing software required
  • Very small engineering effort: simply use the existing ENI file
  • Use the same tool to analyze machines operated by controllers from different manufacturers (Beckhoff, Bosch-Rexroth, Omron, Yaskawa, etc.)
  • No installation of Windows Packet Capture Library & Driver (WinPcap / Npcap) required

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Data sheets and evaluation versions are available in the download area.

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