Adding EtherCAT devices

Requirements

• An EtherCAT master is present in the I/O configuration.
• The device's ESI files are registered in TwinCAT.

Creating EtherCAT devices

To create an EtherCAT master or slave, call CreateChild on the I/O node TIID. The SubType determines the type. EtherCAT masters use 111, while EtherCAT slaves use 130. Configuring network variables via an automation protocol is described in a separate article.

C#:

ITcSmTreeItem devices = sysManager.LookupTreeItem("TIID");

// EtherCAT master (SubType 111)
ITcSmTreeItem etherCatMaster = devices.CreateChild("EtherCAT Master", 111, null, null);

// EtherCAT slave (SubType 130)
ITcSmTreeItem etherCatSlave = devices.CreateChild("EtherCAT Slave", 130, null, null);

PowerShell:

$devices = $systemManager.LookupTreeItem("TIID")
$ethercatMaster = $devices.CreateChild("EtherCAT Master", 111, $null, $null)
$etherCatSlave = $devices.CreateChild("EtherCAT Slave", 130, $null, $null)

Creating EtherCAT Boxes and Terminals with SubType 9099

With a few exceptions, all subordinate devices connected to an EtherCAT master use the common SubType 9099. The exact device variant is specified via the vInfo parameter as a product revision, which is stored in the device's ESI file.

// Create EK1100 coupler
ITcSmTreeItem ek1100 = etherCatMaster.CreateChild("Term 1 (EK1100)", 9099, "", "EK1100-0000-0017");

// Create EL-terminals under coupler
ek1100Item.CreateChild("Term 2 (EL2004)", 9099, "", "EL2004-0000-0017");
ek1100Item.CreateChild("Term 3 (EL2004)", 9099, "", "EL2004-0000-0017");

// Create EL-terminal at specific position (after "Term 3")
ek1100Item.CreateChild("Term 4 (EL2004)", 9099, "Term 3 (EL2004)", "EL2004-0000-0017");

PowerShell:

$ethercatMaster = $systemManager.LookupTreeItem("TIID^EtherCAT Master")
$ethercatMaster.CreateChild("EK1100", 9099, "", "EK1100-0000-0017")

In addition to a full product revision, a wildcard can also be used. If only "EK1100" is specified as vInfo, the Automation Interface automatically detects the latest revision number. The bstrBefore parameter contains the name of the previous child element, not the full path.

CU1128 multi-port coupler

The CU1128 is an EtherCAT switch that consolidates multiple separate EtherCAT segments into a single master connection. After creating the CU1128 node, TwinCAT automatically creates the physical ports as child nodes. Slaves are created directly on the CU1128 node, not on the generated port nodes.

C#:

// Create CU1128 multi-port coupler
ITcSmTreeItem cu1128 = etherCatMaster.CreateChild("A2P (CU1128)", 9099, "", "CU1128");

// Add slaves directly on the CU1128 node (not on child port items)
cu1128.CreateChild("X2 (EK1100)", 9099, "", "EK1100-0000-0001");
cu1128.CreateChild("X3 (EK1100)", 9099, "", "EK1100-0000-0001");

PowerShell:

$cu1128 = $ethercatMaster.CreateChild("CU1128", 9099, $null, "CU1128")
$cu1128_devA = $cu1128.get_Child(1)
$cu1128_devB = $cu1128.get_Child(2)
$ek1100_1 = $cu1128_devA.CreateChild("EK1100-1", 9099, $null, "EK1100")
$ek1100_2 = $cu1128_devB.CreateChild("EK1100-2", 9099, $null, "EK1100")

Exceptions for ItemSubType 9099

Some terminals require a different SubType. The following table lists exceptions:

Configuring the EtherCAT topology: PreviousPort

The PreviousPort of an EtherCAT Terminal determines through which port and which device it is physically connected to the network. In branched topologies with multiple ports, such as those found in an EK1122 coupler, the PreviousPort determines the terminal's logical position in the EtherCAT segment.

<TreeItem>
  <EtherCAT>
    <Slave>
      <PreviousPort Selected="1">
        <Port>B</Port>
        <PhysAddr>1045</PhysAddr>
      </PreviousPort>
      <PreviousPort>
        <Port>B</Port>
        <PhysAddr>1023</PhysAddr>
      </PreviousPort>
    </Slave>
  </EtherCAT>
</TreeItem>

When inserting child nodes directly under a slave, the bstrBefore parameter of CreateChild can be used to determine the insertion position. On an EtherCAT master, however, the topology must be configured via ConsumeXml using the XML structure shown above.

Adding EtherCAT slaves to a HotConnect group

In the TwinCAT Automation Interface, the same result can be achieved on the EtherCAT slave using the following XML structure:

<TreeItem>
  <EtherCAT>
    <Slave>
      <HotConnect>
        <GroupName>Term 1 (EK1101)</GroupName>
        <GroupMemberCnt>4</GroupMemberCnt>
        <IdentifyCmd>
          <Comment>HotConnect-Identität lesen</Comment>
          <Requires>cycle</Requires>
          <Cmd>1</Cmd>
          <Adp>0</Adp>
          <Ado>4096</Ado>
          <DataLength>2</DataLength>
          <Cnt>1</Cnt>
          <Retries>3</Retries>
          <Validate>
            <Data>0000</Data>
            <Timeout>5000</Timeout>
          </Validate>
        </IdentifyCmd>
      </HotConnect>
    </Slave>
  </EtherCAT>
</TreeItem>

Activating the EtherCAT configuration

To activate a TwinCAT configuration via the Automation Interface, you can use ITcSysManager::ActivateConfiguration(). Since the previous steps create an offline configuration without real addresses, the real addresses must be determined and entered using ScanDevices + ProduceXml/ConsumeXml before activation.