Unterschiede

Hier werden die Unterschiede zwischen zwei Versionen angezeigt.

Link zu dieser Vergleichsansicht

Nächste Überarbeitung
Vorhergehende Überarbeitung
embedded_systems:ethercat:ethercatinterface:understanding_ethercatinterface [2019-03-05 15:41] – angelegt mgehrig2embedded_systems:ethercat:ethercatinterface:understanding_ethercatinterface [2019-06-24 16:49] (aktuell) – gelöscht graf
Zeile 1: Zeile 1:
-====== Understanding EtherCatInterface ====== 
-===== ecmasterlib ===== 
-The //"ecmasterlib"// provides a callback function (''void callbackFct(...)'') which is called by the Acontis stack once per EtherCAT cycle. 
-This method: 
-  * Copies the received data from the stack into the receive buffer of //"ecmasterlib"// 
-  * Copies the data to be sent from the send buffer of //"ecmasterlib"// to the stack. 
  
-The receive and send buffers of //"ecmasterlib"// are byte arrays (''uint8_t* inBuffer; uint8_t* outBuffer;'') which are the same size as the PDOs. 
- 
-The //"ecmasterlib"// also provides a condition variable (''std::condition_variable cv;'') to synchronize the user application. 
- 
-When an //"ecmasterlib"// object is created, an instance (monotonic) is created. 
-The stack is started exactly as in the //"EcMasterDemoDC"// of Acontis. 
- 
- 
-===== EtherCatInterfaceBase ===== 
-This is the base class for all interface classes. 
-It mainly provides ''set'' and ''get'' methods for 8, 16, and 32 bit long data. 
-The get methods calculate the correct offset of the receive buffer of the //"ecmasterlib"// and returns the data. 
-The set methods also calculate the offset and write the data into the transmit buffer of //"ecmasterlib"//. 
- 
-==== EtherCatInterfaceBase_config.hpp ==== 
- 
- 
-===== EtherCatInterfaceElmo ===== 
-The //"EtherCatInterfaceElmo"// is especially designed for the Gold Twitter drives from Elmo. 
-It consists of the following components: 
-  * EtherCatInterfaceElmo.hpp 
-  * EtherCatInterfaceElmo.cpp 
-  * EtherCatInterfaceElmo_config.hpp 
- 
-The //"EtherCatInterfaceElmo.hpp"// declares all methods of the interface. 
-The low level methods are at the bottom of the page. 
- 
-These low level methods read and write individual data objects to/from the stack. 
-Which objects are available and their file type must be read from the documentation of the manufacturer of the EtherCAT slave. 
-Each data object has its own method. 
- 
-Where a data object is located in the PDO depends on the ENI file used. 
-These offsets must be read from the ENI file and configured in //"EtherCatInterfaceElmo_config.hpp"//. 
- 
-All methods above the low level methods are optional. 
-They contain a certain degree of intelligence and simplify the interface to the user application. 
- 
-==== Blocking functions ==== 
-Methods in the interface must never be **blocking**. 
- 
-All advanced functions can take several cycles. 
-They are only completed when they return ''true''. 
-These methods must be called again in each cycle until they return ''true''.