2. Digital IO Example

In this example digital inputs and outputs are controlled using the Python programming language. Any industrial component such as light barriers, limit switches or conveyor belts can be connected to these digital IOs and thus programmed with Python.

2.1. Architecture

The architecture of this example is shown in Fig. 2. The voraus EtherCAT Master, to which the EtherCAT devices are connected, runs on an industrial PC (IPC). The master is configured with an EtherCAT Network Information (ENI) file and provides an OPC UA server for the process data. A Python script, which runs on the same IPC, though it does not have to, reads and writes the process data using the voraus-ecat package.

Fig. 2 Digital IO example overview

2.2. EtherCAT Devices

The EtherCAT terminals EK1100 (bus coupler), EL1008 (digital inputs) and EL2008 (digital outputs) from Beckhoff Automation GmbH & Co. KG are used as examples, see Fig. 3. Other EtherCAT devices (like analog IOs, relays, tools, etc.) can also be connected to the voraus EtherCAT Master in the same way.

Fig. 3 EtherCAT devices used in this example (EK1100, EL1008, EL2008)

2.3. Contents

• 2.3.1. Generate ENI-File
  • 2.3.1.1. Open New Project
  • 2.3.1.2. Scan for Devices
  • 2.3.1.3. Export ENI-File
  • 2.3.1.4. Reference ENI-File
• 2.3.2. EtherCAT Master Setup
  • 2.3.2.1. Docker Compose File
  • 2.3.2.2. Executing the Master
• 2.3.3. Generate Python Code
  • 2.3.3.1. Master in Dummy Mode
  • 2.3.3.2. Auto-Generated Code
  • 2.3.3.3. Custom Code
  • 2.3.3.4. Integrate with Version Control System
• 2.3.4. Error Handling
  • 2.3.4.1. Example Code