CPU Unit C200HE-CPU42-E C200HECPU42E C200HE-CPU42-E

Omron C200HE-CPU42-E | C200Hα PLC CPU Unit — 7.2K Words / 880 I/O / Built-In RS-232C

Part Number: C200HE-CPU42-E

Manufacturer: Omron (Japan)

Product Type: PLC CPU Unit — C200Hα Series

Series: C200HE (C200Hα) 

Purpose-Built for C200H System Continuity

The C200HE-CPU42-E is the mid-range CPU unit in the Omron C200Hα family — the PLC platform that defined Omron's automation offer through the 1990s and early 2000s. These systems remain in active service in production facilities worldwide, and the primary reason users source this CPU is continuity: keeping the original program structure, wiring arrangement, and I/O mapping intact without reengineering the control system.

At 7.2K words of program capacity and 880 maximum I/O points across two expansion racks, the C200HE-CPU42-E covers mid-scale machine control — production line coordination, assembly machinery, conveyor systems, and packaging equipment — without requiring a more complex CPU than the application actually needs. The 231 special instructions and 0.3 µs basic execution speed place it well above the minimum for sequence control duties.

The built-in RS-232C port and communications board slot together give the system two independent communication paths: the RS-232C for programming, monitoring, or HMI connection, and the communications board slot for network expansion such as a DeviceNet, PROFIBUS, or Ethernet board. For maintenance engineers working on an installed C200H system, this combination means communication options are not limited to the base serial port.

Backup and Battery

Memory backup covers HR data registers, AR data area, counter current values, DM data, and clock data during power-off. The backup battery has a typical service life of 5 years at 25°C. When the battery alarm appears, it should be replaced with the PLC powered on — replacing with power off risks clearing the retained data if the battery is marginal.

Key Specifications

FAQ

Q1: What is the C200HE-CPU42-E used for?

It is the CPU unit for C200H-based PLC systems — executing ladder programs, managing I/O scanning, coordinating expansion units, and handling RS-232C communication. Typical applications include production equipment, assembly machinery, and conveyor control in existing C200H installations.

Q2: What distinguishes the CPU42-E from the CPU32-E in the same series?

Both are C200HE CPUs, but the CPU42-E provides 7.2K words of program capacity versus the CPU32-E's 3.2K words, and supports the RS-232C port (a CPU4x feature). The CPU42-E is the correct choice when the installed program requires the larger memory or the built-in serial port.

Q3: Does the C200HE-CPU42-E have a built-in communication port?

Yes — one RS-232C port is built in. In addition, the communications board slot accepts optional network boards for DeviceNet, Ethernet, or other protocols, giving the system a second independent communication path.

Q4: How many expansion units can the C200HE-CPU42-E support?

Up to 2 expansion I/O racks, 10 special I/O units, and 10 Group-2 high-density I/O units — allowing the system to grow well beyond the base CPU rack while staying within the C200HE architecture.

Q5: Is the C200HE-CPU42-E still available for a C200H system in production?

The C200H platform is discontinued by Omron. Replacement CPUs are sourced through the industrial PLC aftermarket — tested surplus and exchange units are widely available. The CPU42-E from a compatible source is a direct replacement requiring no program or wiring changes for a like-for-like swap.