CJ1W-DRM21 it is a DeviceNet Master Unit module.
Key features of the CJ1W-DRM21 module include:
DeviceNet Master Unit functionality
Support for up to 64 connections with DeviceNet devices
High-speed data transfer for quick response times
Diagnostics and error reporting capabilities
Configuration via Omron's CX-Integrator software
The module allows the PLC to control and monitor devices on the DeviceNet network, making it suitable for applications where communication with various devices is required. It offers features such as automatic device recognition and easy setup through software configuration.