5.0 KiB
Minimal Example — Analog Input EL3021
Table of Contents
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)
- Insert a screwdriver straight into the square release hole.
- Insert the stripped wire into the round opening.
- Remove the screwdriver — the spring clamp locks the wire.
3.2.2 Wiring Steps (Used in This Example)
We supply power using a DC hollow-plug adapter, like this one:
https://www.amazon.de/dp/B093FTFZ8Q
Perform the following wiring on the EK1100:
- Red wire (+24 V) → Terminal 2
- Black wire (0 V) → Terminal 3
- Jumper wire from Terminal 1 → Terminal 6
- Jumper wire from Terminal 5 → Terminal 7
After wiring, your module should look like Figure 1.
Figure 1 — EK1100 Minimal Wiring
3.3 EL3021 Integration
Slide the EL3021 onto the right side of the EK1100 until it locks.
The EtherCAT E-Bus and power contacts connect automatically.
Then you need to wire the adjustable power supply to the EL3021.
Figure 2 — EL3021 Terminal
- Wire ⊕ to Terminal 1
- Wire ⊖ to Terminal 2
3.4 Final Assembled Setup
Figure 3 — EK1100 + EL3021 Connected
3.5 Power & Ethernet
3.5.1 Power
Connect the 24 V adapter to the hollow plug used earlier.
Example AC/DC Adapter (Figure 4):
3.5.2 Ethernet
Use a standard LAN cable to connect your PC → EK1100. The final powered up and connected setup should look like this:
4. Software Setup
4.1 Installing on Ubuntu/Debian
Paste this into your terminal:
# Press Enter when prompted
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
sudo apt update
sudo apt install -y npm nodejs git
git clone git@github.com:qitechgmbh/control.git
cd control/electron
npm install
4.2 Running the Backend
./cargo_run_linux.sh
This script:
-
Builds the backend
-
Grants required system capabilities (raw sockets)
-
Starts EtherCAT communication
Ensure the EK1100 is connected.
4.3 Running the Frontend
cd electron
npm run start
This launches the QiTech Control dashboard.
5. Demo
5.1 Assigning Devices in the Dashboard
Once both backend and frontend are running, the Setup -> EtherCat page should look something like this:
Listing the EK1100 and the EL3021.
To assign the two devices to a machine, click "Assign" on both devices. This should open the following pop-up modal:
EK1100
- Select "AnalogTest V1" under "Machine"
- Choose a serial number to uniquely identify the machine (1 in this example)
- Under "Device Role" select "0 - Bus Coupler"
EL3021
- Select "AnalogTest V1" under "Machine"
- Use the same serial number you chose for the EK1100
- Under "Device Role" select "1 - EL3021"
The machine is now configured.
A new Tab "AnalogTest" should appear in the right sidebar. Clicking that tab should show the machine control interface:
Results should show the current measured by the analog input - the current set on the adjustable power supply.
6. References
This guide incorporates information from official Beckhoff documentation. All diagrams, product names, and figures belong to Beckhoff Automation GmbH & Co. KG and are used here solely for educational purposes.
Referenced Manuals