TwinCAT Example using NC and EtherCAT

This TwinCAT 3 application example helps you getting started to use a Triamec drive with EtherCAT fieldbus.

Note

Example tested with TwinCAT v3.1.4024.56 and following libraries:

Prerequisites

The following prerequisites have to be met using this example code.

• A TwinCAT 3 runtime system (3.1.4024 or newer) with an EtherCAT-Master.
• Triamec EtherCAT Lib 2.1.0 or newer installed. Available as download from triamec.com.
• Drive commissioned. Checkout the Servo Drive Setup Guide from the documents page.
• Drive controlled homing configured on the drive (Axes[0]/Parameters/Homing). Checkout AN141 from the documents page.
• All drives must be powered and connected to the EtherCAT-Master.

EtherCAT-Master Adapter

Open adapter settings for the EtherCAT-Master in I/O > Devices > Device 1 (EtherCAT) > Adapter.

Press Search... fo find the adapter on your system.

Note

Make sure, that TwinCAT is in Config Mode before you search the EtherCAT Master Adapter.

TwinCAT SYSTEM

Make sure to use an isolated core on the TwinCAT PC. As each PC is different, ensure to set up the SYSTEM > Real-Time > Settings accordingly.

Global Variable List (Triamec_GVL)

The following global variables have been defined to control and monitor the axes.

Variable	Description
gEnableAxes	variable to enable all axes
gStatusAxesEnabled	variable indicates that all axes enabled
gHoming	variable to execute drive controlled homing

NC Axis Function Block (NC_Axis)

The function block extends TE_AxisBase0 available in the Triamec EtherCAT Lib by the NC specific interfaces. It makes use of TwinCAT motion control PLC library function blocks (MC_Power / MC_Reset) to control the axis The NC_Axis contains an instance of DriveControlledHoming function block, which allows to execute the drive controlled homing.

Test the Example

• Save and Rebuild the Solution.
• Activate the configuration and set TwinCAT to Run Mode.
• Login and Start the PLC.
• Open Triamec_GVL and enable the axes by setting gEnableAxes to TRUE, check gStatusAxesEnabled if all axes are enabled.

Ready to move the axes

You should now be able to control the axes over NC Axis GUI (Online GUI). The buttons -- F1, - F2, + F3 and ++ F4 are in the MOTION > NC-Task 1 SAF > Axes > Axis N > Online dialog.

Drive controlled homing

While axes are enabled, gEnableAxes and gStatusAxesEnabled are TRUE, start the drive controlled homing by setting gHoming to TRUE. The configured homing will start. An successful homing will be indicated by the NC_Axis.referenced output.

Note

For drive controlled homing, the following two EtherCAT signals are mapped to the I/O variables of DriveControlledHoming function block:

I/O MainOutputs/Mode of Operation --> MAIN.Axis[].drvHoming.modeOfOperation

I/O MainInputs/Status Word --> MAIN.Axis[].drvHoming.statusWord (and to NC Axis)