CQM1H-CPU21
The CQM1H-CPU21 is a compact, rack-less Programmable Logic Controller (PLC) CPU module manufactured by OMRON Corporation. It belongs to the legacy SYSMAC CQM1H series, widely used for small-to-medium scale industrial automation.

• Built-in Inputs: 16 DC digital inputs (24 VDC).
• Program Capacity: 7.2 Kwords of user program memory.
• Data Memory: 6 Kwords of Data Memory (DM) area.
• Communication Ports: One built-in RS-232C port and one Peripheral port.
• Inner Board Slots: 1 dedicated slot for expanding advanced functions (e.g., High-speed Counter, Analog I/O, or Pulse Output boards).
• Max I/O Capacity: Expandable up to 512 points (with a maximum of 11 expansion modules).

• Programming Software: Confured and programmed using OMRON's CX-Programmer (part of the CX-One software suite).
• Connection Cable: Connects to a PC via the CS1W-CN226 / CS1W-CN626 cable. A reliable USB-to-RS232 converter is required if your PC lacks a native DB9 serial port.