From 883d24349d69a0159b5f37c97200f2a32d26016d Mon Sep 17 00:00:00 2001 From: Florian Pose <fp@igh-essen.com> Date: Wed, 22 Oct 2008 11:53:40 +0000 Subject: [PATCH] VoE handlers. --- documentation/ethercat_doc.tex | 42 +++++++++++++++++++++++++--------- 1 file changed, 31 insertions(+), 11 deletions(-) diff --git a/documentation/ethercat_doc.tex b/documentation/ethercat_doc.tex index ce1ea96a..98d60dae 100644 --- a/documentation/ethercat_doc.tex +++ b/documentation/ethercat_doc.tex @@ -571,7 +571,6 @@ physical memory to logical process data images. % Pdo entry registration % Sdo configuration % Sdo access -% VoE handlers The application interface provides functions and data structures for applications to access an EtherCAT master. The complete documentation of the @@ -710,6 +709,35 @@ frames. %------------------------------------------------------------------------------ +\section{VoE Handlers} +\label{sec:api-voe} + +During the configuration phase, the application can create handlers for the +VoE mailbox protocol described in sec.~\ref{sec:voe}. One VoE handler always +belongs to a certain slave configuration, so the creation function is a method +of the slave configuration. + +A VoE handler manages the VoE data and the datagram used to transmit and +receive VoE messages. Is contains the state machine necessary to transfer VoE +messages. + +The VoE state machine can only process one operation at a time. As a result, +either a read or write operation may be issued at a time\footnote{If +simultaneous sending and receiving is desired, two VoE handlers can be created +for the slave configuration.}. After the operation is initiated, the handler +must be executed cyclically until it is finished. After that, the results of +the operation can be retrieved. + +A VoE handler has an own datagram structure, that is marked for exchange after +each execution step. So the application can decide, how many handlers to +execute before sending the corresponding EtherCAT frame(s). + +For more information about the use of VoE handlers see the documentation of +the application interface functions and the example applications provided in +the \textit{examples/} directory. + +%------------------------------------------------------------------------------ + \section{Concurrent Master Access} \label{sec:concurr} \index{Concurrency} @@ -1969,17 +1997,9 @@ constraints regarding this protocol. The EtherCAT master allows to create multiple VoE handlers per slave configuration via the application interface (see chap.~\ref{chap:api}). These handlers contain the state machine necessary for the communication via VoE. -One read or write operation may be issued at a time. After the operation is -initiated, the handler must be executed cyclically until it is finished. After -that, the results of the operation can be retrieved. - -A VoE handler has an own datagram structure, that is marked for exchange after -each execution step. So the application can decide, how many handlers to -execute before sending the corresponding EtherCAT frame(s). -For more information about using VoE handlers, see the application interface -documentation (chap.~\ref{chap:api}) or the example applications provided in -the \textit{examples/} subdirectory. +For more information about using VoE handlers, see sec.~\ref{sec:api-voe} or +the example applications provided in the \textit{examples/} subdirectory. %------------------------------------------------------------------------------ -- GitLab