TwinCAT 3 project with CODESYS PLC

The example describes how to generate a PLC project (without TwinCAT NC axis / CNC axis).

In the PLC example project, the PLC controls and evaluates 'Master Control Word' and 'Drive Status Word'.

 

Start TwinCAT XAE (VS 2013)

 

Create a new project

 

 

Select the target system:

 

Add the EtherCAT Master functionality to the ‘Device’ icon

 

 

Activate existing network adapter

 

Driver installed

Activate the adapter

 

Driver not installed

Siehe Adapter settings.

 

Scanning a network

Scanning is only possible with an activated network adapter.

 

Scanning is only possible in TwinCAT ‘Config Mode’.

 

Creating a PLC project

 

 

The standard value of the TwinCAT PLC task is 10 ms.

The cycle time is entered via the ‘PlcTask’ icon.

 

When the TwinCAT ‘Activate Configuration’ function is executed, the set PLC task value (cycle time) is automatically transferred to the AMK drive (ID1 'NC cycle time' and 'SERCOS cycle time')

 

The cycle times become active with the next initialization in the AMK drive.

(System reset command, or 24 VDC OFF/ON)

 

For differing values, TwinCAT generates the status code ‘0x0037 - invalid SYNC1 cycle time’.

 

Opening PLC MAIN program module

 

PLC variables

Variables declaration

Direction

‘Variable name’ AT %I* : ’Declaration’

Input variable

Axis → PLC

‘Variable name’ AT %Q* : ’Declaration’

Output variable

PLC → axis

 

 

PLC project ‘Transfer’

 

 

Connection between EtherCAT slave device and a task variable is missing, so that the cycle time cannot be determined.

Bus start-up remains stuck in PREOP bus state.

Options for a solution can be, e.g. to connect the Status Word drive in the AT with a PLC variable or using the NC/CNC axis.

 

Linking variables

 

 

Creating a network configuration

 

Start TwinCAT 'Run Mode'

 

When the TwinCAT ‘Activate Configuration’ function is executed, the set PLC task value (cycle time) is automatically transferred to the AMK drive (ID1 'NC cycle time' and 'SERCOS cycle time')

 

The cycle times become active with the next initialization in the AMK drive.

(System reset command, or 24 VDC OFF/ON)

 

For differing values, TwinCAT generates the status code ‘0x0037 - invalid SYNC1 cycle time’.

 

Log-in: transfer PLC program to the control unit

 

Start PLC

 

Function test: online values are displayed and updated