Here are some key features of the CQM1H-CPU21 PLC module:

Central Processing Unit (CPU): The CPU21 is the main component of the CQM1H-CPU21 module. It provides the processing power to execute ladder logic programs and perform various control functions. The CPU21 has a 10K-step program capacity and supports ladder programming languages.

Program Memory: This module has a built-in EEPROM (Electrically Erasable Programmable Read-Only Memory) for storing ladder programs. The EEPROM ensures that the program remains stored even when power is lost.

Communication Ports: The CQM1H-CPU21 offers two serial communication ports: Port 1 and Port 2. These ports can be used for communication with external devices such as Human-Machine Interfaces (HMIs), programming,devices, or other PLCs

Input and Output (I/O): The CQM1H-CPU21 module supports a variety of input and output signals. It has the capacity to handle digital inputs and outputs (DI/DO), analog inputs (AI), and analog outputs (AO) using additional I/O modules.

Expansion: The CQM1H-CPU21 is expandable, allowing for the connection of additional I/O modules to accommodate larger-scale control systems. Expansion racks and modules can be added as per the application requirements.

Programming and Software: The CQM1H-CPU21 can be programmed using Omron's CX-Programmer software, which provides a user-friendly environment for ladder logic programming, configuration, and monitoring of the PLC.