The "EK1818" module you mentioned is a digital input module manufactured by Beckhoff Automation. Beckhoff is a company that specializes in automation and control technology, providing a wide range of industrial control systems and components.

The EK1818 module is part of Beckhoff's EtherCAT I/O system, which is a distributed I/O system that allows for decentralized control and data acquisition. The EK1818 module specifically is designed to provide digital input signals to the control system.

Some key features of the EK1818 module include:

1. Digital Inputs: The module offers 8 digital input channels, allowing the connection of various sensors, switches, or other digital devices.

2. Input Type: The EK1818 module supports both 24 V DC digital inputs and 24 V DC pulse inputs. This allows flexibility in connecting different types of devices.

3. Diagnostic LEDs: The module is equipped with diagnostic LEDs for each input channel, providing visual feedback on the status of the inputs.

4. EtherCAT Connectivity: The module communicates with the control system or PLC (Programmable Logic Controller) over the EtherCAT fieldbus. EtherCAT is a high-speed industrial Ethernet protocol used for real-time communication in automation systems.

5. DIN Rail Mounting: The EK1818 module is designed for DIN rail mounting, which is a common mounting method in industrial control panel installations.

It's important to note that programming and configuring the EK1818 module would typically be done using Beckhoff's automation software, such as TwinCAT. The software provides a development environment for programming the control logic, configuring the I/O, and integrating the module into the overall automation system.

Overall, the Beckhoff EK1818 module is a digital input module that allows for the integration of digital signals into a Beckhoff EtherCAT-based control system, enabling the monitoring and control of digital devices in industrial automation applications.