The Omron CJ2M-CPU33, also cataloged as the CJ2M-CPU33 CPU Units, operates as a dedicated hardware component for centralized logic execution and network communications within Omron CJ2M automation platforms.

Technical Identifier Matrix

• Base Part Number: CJ2M-CPU33
• Series Platform: CJ2M Series
• Product Classification: CPU Unit (Built-in EtherNet/IP)
• Embedded Communications: EtherNet/IP, Ethernet TCP/IP, USB 2.0

Hardware Specifications

EtherNet/IP Determinism and Backplane Bus Velocity

The Omron CJ2M-CPU33 integrates an independent EtherNet/IP network processor that operates without burdening the core instruction execution cycle. Reaching ladder instruction execution speeds of 0.04 us (40 ns), the unit ensures precise timing loops while simultaneously managing cyclic implicit messaging and explicit TCP/IP data transfers.

The internal backplane bus handles up to 40 expansion units scaled across 3 expansion racks, delivering deterministic update cycles for up to 2560 digital I/O points. Current draw is maintained at 0.70 A (700 mA) on the internal 5 VDC backplane rail. The CPU panel features an option board slot allowing field-installation of RS-232C, RS-422A/485, or Pulse I/O daughter cards without expanding the physical footprint.

Package Contents & Ordering Information

• 1x Omron CJ2M-CPU33 CPU Unit
• 1x CJ1W-BAT01 Backup Battery
• 1x Protective USB Connector Cover
• 1x Hardware Installation Sheet

Field Installation Guidelines

• Cabinet Mounting: Install the CPU module on a standard 35 mm DIN rail or panel baseplate within an IP54 control cabinet. Maintain at least 30 mm vertical clearance above and below the housing for heat dissipation.
• Backplane Assembly: Slide the CPU flush against the adjacent CJ-Series power supply module. Engage the top and bottom slider latches until an audible click confirms proper bus pin mating.
• Grounding Requirements: Wire the functional ground (FG) terminal on the rack power supply module to earth ground using a conductor of 2.0 mm sq. minimum. Verify the earth loop resistance measures under 100 ohm.
• EtherNet/IP Cabling: Connect Category 5e or Category 6 STP cable to the RJ45 port. Route communication cables in separate raceways away from high-voltage AC motor drives.
• Shielding: Connect communication cable braids to the connector shroud to establish a 360-deg braid shield against industrial electromagnetic noise.

Frequently Asked Questions

• What is the execution speed of a standard LD instruction on the CJ2M-CPU33?

  The processor executes basic ladder (LD) instructions in 0.04 us (40 ns).

• What is the total current draw of the CJ2M-CPU33 on the 5 VDC backplane supply?

  The module draws 0.70 A (700 mA) at 5 VDC directly from the backplane power supply module.

• How many expansion racks and units can be connected to a single CPU rack?

  The controller supports a maximum of 40 mountable units distributed over up to 3 expansion racks.

• What is the memory structure and capacity for user programs and data storage?

  The controller features 20K steps of program capacity and 64K words of data memory split into 32K words DM and 32K words x 1 bank EM.

• What communication ports are natively available on the front face of the unit?

  The CPU features an embedded EtherNet/IP port, a peripheral USB port, and one dedicated option board slot.

• What option boards can be installed into the built-in option board slot?

  The slot accepts optional serial communication boards (RS-232C, RS-422A/485) or Pulse I/O modules.

• Can the CJ2M-CPU33 CPU be hot-swapped while the CJ backplane power is active?

  No, the power supply module feeding the CPU rack must be switched off prior to mounting or removing the CPU unit.

• What is the grounding requirement for the system functional ground?

  The functional ground line must be connected to an earth ground maintaining a resistance value of less than 100 ohm.