qitech-control/docs/developer-docs/minimal-example-el3021.md

Minimal Example — Analog Input EL3021

Table of Contents

1. Introduction
2. Requirements
3. Hardware Setup
4. Software Setup
5. Demo
6. References

1. Introduction

The EL3021 Analog Input example demonstrates how to measure analog current on a Beckhoff EL3021 EtherCAT terminal using the QiTech machine framework.

2. Requirements

Hardware

• Beckhoff EL3021 EtherCAT Terminal (1-channel analog input)
• Beckhoff EK1100 EtherCAT Coupler
• 24 V DC power supply (AC/DC adapter + DC hollow plug)
• Adjustable DC power supply (or any other means of producing 4-20mA DC @ <10V )
• Jumper / bridge wires (0.5–1.5 mm² recommended)
• A Linux PC (Ubuntu/Debian recommended)
• Standard Ethernet cable
• Flat screwdriver

3. Hardware Setup

3.1 Schematic

The 24V supply powers the EL2004, while the adjustable power supply generates the analog input signal for the EL3021.

⚠️ Safety Warning

Always disconnect power before wiring.
Working on live EtherCAT terminals can cause serious damage or electrical shock.

3.2.1 Safe Wiring Procedure (Beckhoff Recommended)

1. Insert a screwdriver straight into the square release hole.
2. Insert the stripped wire into the round opening.
3. Remove the screwdriver — the spring clamp locks the wire.