-
EtherCAT
入门教程
本文翻译了
kithara
官方文档，
也加入了一些理解，
暂时
做得还不够完美，后续补充修正。
2014.06.06
EtherCAT
This tutorial
describes the following topics using the EtherCAT
API
本向导描述了使用
EtherCAT
API
的功能说明
Creating a
EtherCAT master assigned to a network
adapterCreating slaves
assigned to the
masterReal-time process data exchange with
datasets and assigned PDOsReal-time
up/download of service
data objects
(SDO)Real-time mailbox communicationState
control for master and slavesGetting
information for master,
slaves, data
objects, variable objects
中文说明创建
< br>EtherCAT
主
站使用的网卡创建连接主站的从站使
用
dataset
和
PDO
进行
实时过程数据交互
Master
related functions----
主站相关功能
Opening a network
adapter----
打开网卡
Before we can create a master, it is
necessary to open a network
adapter
first. This is done by using the function
KS_openAdapter. As parameters an
adapter name, a receive and
a send pool
size is needed. The adapter name is usually the
name
of a network device. The function
KS_enumDevices enumerates
all devices.
To only get network devices the parameter
deviceType is set to “NET”.
在创建主站之前，
必须打开网卡。
使用
KS_openAdapter
函数
打
开网卡，需要的参数包括网卡名称，收发数据池大小等。
可以使用
KS_enumDevices
枚举设备获取网卡名称，使用该
函数时参数
deviceType
应该设置为“
NET
”
Mind
that the function KS_openAdapter must be called
with the
flag KSF_REALTIME_EXEC.
使用
KS_openAdapter
时需要将标志位
flag
设置为
KSF_REALTI
ME_EXEC
，
表明网卡运行在实时模式。
< br>ksError
= KS_enumDevices(
//
枚举设备
// Searches for
network devices
deviceIndex,
//
Count, starting with
zero
pDeviceName,
// Buffer for device
name
0);
//
Flags
if (ksError)
// ...ksError = KS_openAdapter(
//
打开网卡
&hAdapter,
//
Adapter
handle pointer
pDeviceName,
// Hardware ID of
the Controller
256,
//
Receive Pool
Length
256,
// Send Pool Length
KSF_REALTIME_EXEC);
//
Flags
if (ksError)
// ...For further details see How to
look up for devices.
Creating a
master----
创建主站
To
create a master the function KS_createEcatMaster
can be
used. As parameters a network
adapter handle and a path to
device
description XML files are needed. A name of a
topology
file (*.ktp) is optional. The
device description XML files can be
found with a developer installation in
the XML directory or can
be downloaded
from the slave manufacturer website. A topology
file can be created with the Kithara
?Master Monitor?.
使用
KS_creat
eEcatMaster
创建主站，
需要传入网卡句柄参数
和从站
XML
设备描述文件路径，也可以加
入一个拓扑文件
ktp
参数。设备描述文件可以从设备制造商的
网站上获取。
拓扑文件可以用
Master
Monitor
生成。
The
Kithara ?Master Monitor? is a tool for e.g.
configuration,
diagnostics and saving
XML configuration files for graphically
viewing slaves, objects and variables
or comparing a given
topology with a
target topology.
Master Monitor
< br>是一个用于配置、调试和保存
xml
配置文件
的图形化工具，
可以查看从站、
对象、
变量和对比拓扑文件。
Closing a
master----
关闭主站
To
close a master and free all its resources the
function
KS_closeEcatMaster must be
used.
使用
KS_closeEcatMaster
关闭从站
State change
for a master----
主站的状态切换
To query and change the master's state
the functions
KS_queryEcatMasterState
and KS_changeEcatStatecan be used.
用
KS_queryEcatMasterState
查询主站状态。<
/p>
用
KS_changeEcatSta
te
改变主站状态。
The
function KS_queryEcatMasterState needs a master
handle,
a pointer to the
structureKSEcatMasterState and flags. Be sure
to initialize the structure member
structSize to the actual size of
the
structure KSEcatMasterState before calling the
function.
The
function KS_changeEcatState needs a master handle,
the
requested state and flags as
parameters. The state of all assigned
slaves which are online is changed.
Slaves are assigned using
the
functionKS_createEcatSlave or
KS_createEcatSlaveIndirect.
Nearly every EtherCAT API
function has special requirements
regarding the state (see the
APIdocumentation of the specific
function). For further information
about the state machine see
The
EtherCAT state machine.
几乎每一个
EtherCAT
的
API
函数都需
要主站在特定的状态
才能使用。
Slave related
functions----
从站相关函数
Enumerating all online
slaves----
枚举所有在线从站
After a master was created, all online
slaves can be enumerated
using the
function KS_enumEcatSlaves. As parameters a master
handle, a enumeration index and a
pointer to the structure
KSEcatSlaveState are needed. Be sure to
initialize the structure
member
structSize to the actual size of the
structureKSEcatSlaveState before
calling the function.
主站创建之后，则可以使用
KS_enumEcatSlaves
枚举所有从
站
.
需要的参数包括主站句柄、枚举顺序、一个
KSEcatSlaveState
结构体的指针。在使用前应当初始化结构<
/p>
体的成员变量
structSize
大小
。
If the enumeration index
is greater than the number of online
slaves, the error
codeKSERROR_DEVICE_NOT_FOUND is
returned. Otherwise, a pointer to the
structure KSEcatSlaveState
is returned
which contains information about the slave's
state.
Using
the function KS_enumEcatSlaves the slaves are
enumerated by their absolute position.
Creating a
slave----
创建从站
To
create a slave, one of the functions
KS_createEcatSlaveIndirect or
KS_createEcatSlave can be used.
The
function KS_createEcatSlaveIndirect makes use of
the
structure KSEcatSlaveState which
can be obtained using the
function
KS_enumEcatSlaves.
The function
KS_createEcatSlave needs additional parameters
like slave id, position, vendor id and
revision number. With the
parameter
slave id a relative position can be provided, too.
The parameters are unique to a slave
type. This information can
be found in
the slave's manual, using the method above with
the
structure KSEcatSlaveState or can
be displayed with the
Kithara ?Master
Monitor?.
If a slave is already
assigned and the function
KS_createEcatSlave is called with the
same vendor ID, product
ID, revision
number and position, an error
KSERROR_DEVICE_ALREADY_USED is returned
together
with a slave handle to the
already assigned slave.
Deleting a
slave----
删除从站
A
slave can be deleted using the function
KS_deleteEcatSlave.
Getting information
from slaves----
获取从站信息
To query information from a slave the
function
KS_queryEcatSlaveInfo can be
used. It delivers a pointer to the
structure KSEcatSlaveInfo. If
information about process data
objects
(PDO), service data objects (SDO) or both are
needed,
the flags KSF_SDO and KSF_PDO
can be passed to the
function. The
function is time consuming (up to 30 seconds) and
the state PREOP or higher is needed for
online slaves.
Within the structure
KSEcatSlaveInfo there is an array of
KSEcatDataObjInfo and within this
structure there is an array of
KSEcatDataVarInfo.
If using
languages like C# these structured cannot be
accessed.
Alternatively, the
functionsKS_queryEcatDataObjInfo,
KS_queryEcatDataVarInfo,
KS_enumEcatDataObjInfo
andKS_enumEcatDataVarInfo can be used
instead.
State changes for
slaves----
从站状态机改变，与主站类似
To query and change the slave's state
the functions
KS_queryEcatSlaveState
and KS_changeEcatState can be used.
查询和
改变从站状态可以用以上两个函数，改变状态的函数
与改变主站的相同
< br>
The function KS_queryEcatSlaveState
needs a slave handle, a
pointer to the
structure KSEcatSlaveStateand flags. Be sure to
initialize the structure member
structSize to the actual size of the
structureKSEcatSlaveState before
calling the function.
查询从站状态函数，需要一个从站句柄
、指向
KSEcatSlaveState
结构体的指针和标志
位。使用前请初始化
结构体内部的
structSize
变量。
For further
information concerning the state machine see The
EtherCAT state machine.
更多的信息可以查看此章节
Other operations on
slaves----
从站的其他操作
Using the function KS_writeEcatSlaveId
it is possible to write a
unique ID to
any slave. The ID is written to non-volatile
memory and will be persistent. Within a
connected real topology
the IDs must be
unique. Mind that the slave must be in INIT
state.
使用
KS_write
EcatSlaveId
函数可以给从站写入唯一的
ID
。
ID
必须是唯一的，注意此时从站的状态必
须是
INIT
Dataset related
functions----Dataset
相关函数
A dataset is a collection of sync
managers, a sync manager can
contain
several PDOs (process data objects) and a PDO can
be
mapped to multiple SDO (service data
object) variables. A sync
manager is a
slave internal mechanism to keep data consistent.