--- a/documentation/ethercat_doc.tex	Wed Nov 05 15:01:04 2008 +0000
+++ b/documentation/ethercat_doc.tex	Wed Nov 05 15:27:14 2008 +0000
@@ -2196,24 +2196,25 @@
 
 %------------------------------------------------------------------------------
 
-\section{Monitoring and Debugging}
+\section{Debug Interfaces}
 \label{sec:debug}
-\index{Monitoring}
+\index{Debug Interfaces}
 
 EtherCAT buses can always be monitored by inserting a switch between master
 and slaves. This allows to connect another PC with a network monitor like
 Wireshark~\cite{wireshark}, for example.
 
-For convenience, so-called ``debug interfaces'' are supported. Debug interfaces
-allow to monitor EtherCAT traffic with a network monitor (like Wireshark or
-tcpdump) running on the same machine. To use this functionality, the master
-sources have to be configured with the \lstinline+--enable-debug-if+ switch
-(see sec.~\ref{sec:installation}).
+For convenience, so-called ``debug interfaces'' are supported. Debug
+interfaces allow to monitor EtherCAT traffic with a network monitor (like
+Wireshark or tcpdump) running on the master machine without using external
+hardware. To use this functionality, the master sources have to be configured
+with the \lstinline+--enable-debug-if+ switch (see
+sec.~\ref{sec:installation}).
 
 Every EtherCAT master registers two read-only network interfaces. These are
-named \textit{ecdbgmX} (main device) and \textit{ecdbgbX} (backup device for
-future use), where X is the master index. The debug interfaces are listed in
-the below output:
+named \textit{ecdbgmX} (main device) and \textit{ecdbgbX} (backup device, for
+future use), where X is the master index. The below listing shows debug
+interface among some standard interfaces:
 
 \begin{lstlisting}
 # `\textbf{ip link}`
@@ -2228,9 +2229,9 @@
     link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
 \end{lstlisting}
 
-While a debug interface is enabled, the corresponding master forwards all
-frames sent and received to or from the bus to that interface. Interfaces can
-be enabled for example with the command:
+While a debug interface is enabled, all frames sent or received to or from the
+physical device are additionally forwarded to the debug interface by the
+corresponding master. Interfaces can be enabled with the below command:
 
 \begin{lstlisting}
 # `\textbf{ip link set dev ecdbgm0 up}`