How does the X20 controller connect to X20 I/O modules? You can read article here

### Physical Connection
1. Backplane Bus
The X20 controller and I/O modules are physically connected via a backplane bus. All modules mount on a common backplane. The backplane offers mechanical support and electrical conductors for power, data, and control - signal transfer. Each module connects to the backplane through a dedicated connector.

2. Module Arrangement
Modules are arranged in a specific order on the backplane. The X20 controller usually sits at one end, and I/O modules are added next according to system needs. The module order determines their system addresses for communication.

### Communication Protocol
1. POWERLINK
B&R's POWERLINK, a high - speed real - time Ethernet fieldbus protocol, is used for communication between the X20 controller and I/O modules over the backplane bus. It provides deterministic communication, ensuring data is transmitted at predictable intervals for precise synchronization. The controller manages the communication cycle, requesting input data from I/O modules and sending output data to them. I/O modules respond within defined time slots.

Configuration and Addressing
1. Configuration Software
B&R Automation Studio configures the X20 system. Users can define module types and addresses, set communication parameters like baud rate and data format for the POWERLINK network, and create control programs to interact with I/O modules.

2. Addressing
Each X20 I/O module has a unique system address, based on its physical position on the backplane and configurable in Automation Studio. This helps the controller accurately read input and send output data as needed.

X20 controller: including multiple models, such as [X20CP1584](https://www.cwlyautomation.com/product/6157.html "X20CP1584"), [X20CP3585](https://www.cwlyautomation.com/product/6184.html "X20CP3585"), etc. The X20 series controller has the characteristics of high performance, compact design and rich communication interfaces, and can be widely used in various industrial automation scenarios. Its width is only 37.5mm (including power supply), which is the most compact among similar products. It also comes with Powerlink, Ethernet, USB and RS232 interfaces as standard, and CAN interface is optional to meet the communication needs of different devices.

X20 I/O modules: such as [X20DI4371](https://www.cwlyautomation.com/product/6159.html "X20DI4371") digital input module, [X20DO4332](https://www.cwlyautomation.com/product/6160.html "X20DO4332") digital output module, [X20AI1744](https://www.cwlyautomation.com/product/6161.html "X20AI1744") analog input module, [X20AO4622](https://www.cwlyautomation.com/product/6178.html "X20AO4622") analog output module, etc. These modules can be easily connected to the X20 controller to realize the input and output of various signals, providing flexible configuration options for the automation system.