Configured for central logic execution and direct pulse I/O management in SYSMAC CJ1 Series platforms, the Omron CJ1M-CPU21 (CJ1M-CPU21 CPU Processor Module) provides direct physical/electrical execution.

Technical Identifier Matrix

• Brand: Omron
• Base Model: CJ1M-CPU21
• Full Part Number: CJ1M-CPU21
• Series Name: SYSMAC CJ1 Series
• Product Type: CPU Processor Module
• System Platform: SYSMAC CJ1

Hardware Specifications

PLC Controller Processing & Backplane Communication

The CJ1M-CPU21 unit executes fundamental boolean LD instructions in 100 ns and data MOV instructions in 0.3 us, maintaining a system cyclic overhead time of 0.7 ms. The internal processing architecture manages up to 10 local CJ1 Special I/O and standard I/O units directly across the local backplane bus without supporting expansion racks. Integrated pulse control interfaces deliver pulse start timing of 63 us without acceleration/deceleration and 100 us with trapezoidal profiles across two 100 kHz pulse output channels. Firmware flash memory supports program density scaling up to 5 Ksteps alongside 32 Kwords of dedicated DM data memory.

Package Contents & Ordering Information

• 1x Omron CJ1M-CPU21 CPU Processor Module
• 1x CJ1 System Bus End Cover

Field Installation Guidelines

• Mounting: Mount the CPU unit directly onto the DIN rail at the left-most position of the CJ1 CPU rack assembly and secure the end locks.
• Wiring: Terminate built-in I/O field conductors using removable terminal connectors, maintaining separation from high-voltage AC lines.
• Shielding: Connect high-speed counter and pulse output cables using twisted pairs protected by 360-deg braid shielding bonded to functional earth.
• Grounding: Wire the main CPU rack functional earth (FE) terminal directly to the panel system grounding bar via a dedicated low-impedance copper strap.

Frequently Asked Questions

• Does the CJ1M-CPU21 support connection to CJ1 expansion racks?

  No, the CJ1M-CPU21 CPU model does not support expansion racks and is limited to a maximum of 10 connectable units on the CPU rack.

• What memory capacities are integrated into the CJ1M-CPU21 CPU Processor Module?

  The processor provides 5 Ksteps of ladder program memory capacity and 32 Kwords of DM data memory capacity (EM memory is not supported).

• What high-speed counter signal modes are accepted by the built-in input channels?

  The 2 built-in high-speed counter inputs accept 50 kHz phase-differential inputs or 100 kHz single-phase pulse inputs.

• What communication interfaces are integrated on the CPU front panel?

  The CPU features 1 peripheral port for direct programming tool connection and 1 RS-232C serial communication port.

• What is the execution speed of basic instructions on the CJ1M-CPU21?

  The module processes basic LD instructions in 100 ns and memory MOV data transfer instructions in 0.3 us.

• What physical envelope dimensions apply to the CJ1M-CPU21 unit?

  The CPU module physical dimensions measure 4.9 cm x 9.0 cm x 6.5 cm with a net unit weight of 0.19 kg.

• What built-in pulse generation outputs are available on the terminal block?

  The unit provides 6 built-in digital outputs, which include 2 pulse output channels operating up to 100 kHz and 1 PWM output channel.

• What external removable memory media can be inserted into the CPU card slot?

  The CPU module includes an integrated Memory Card interface slot designed to accept industrial CompactFlash memory cards.