BECKHOFF ET2000 - Manual (Page 12)

Product overview
Fig. 5: Screenshot of a Wireshark recording
Fig. "Screenshot of a Wireshark recording" shows a log of EtherCAT frames from the TwinCAT EtherCAT
master; in the windows underneath, the content of a frame is broken down (if possible). The "Time" column
shows the time at which the frame transmitted by the ET2000 arrived at the PC's Gbit port. Because this
involves passage through a number of Windows protocol layers, the accuracy of these values must be
considered carefully.
Operation with ESL/time stamp evaluation
If no other actions are taken, the data in the "Time" column gives the approximate arrival time of the Ethernet
frame transmitted by the ET2000 on the PC's Gbit port. This value may deviate significantly from the pass­
through time of the original frames through the ET2000. Evaluation of the time stamp added by the ET2000
requires a Wireshark extension made available by Beckhoff for Wireshark version 1.0.2 and above. This is a
modified EtherCAT parser "ethercat.dll", which ensures that Wireshark can break down an Ethernet frame
with EtherCAT datagrams into its components (see Fig. "Screenshot of a Wireshark recording").
Replacing the standard ethercat.dll enables Wireshark to read the ESL information, although Ethernet
frames not containing ESL will no longer be recorded.
This dll file is available for download from http://www.beckhoff.com under Download ­­> Software ­­>
Development products. The Wireshark installation already contains a EtherCAT.dll, as the case may be, this
file does not support the ESL protocol yet. Once the existing Ethercat.dll in folder Wireshark/plugins/<build>/
has been replaced, this dissector (for breakdown) can be activated under Edit/Preferences (see Fig.
"Activation of the ESL Dissector in "Wireshark""). The "Time" column of the Wireshark interface then displays
the time stamp applied by the ET2000; otherwise the time at which the frame arrived at the PC's Gbit port is
displayed.
ET2000 12 Version 2.0