Bachmann ME200 Series Modules: ME203/CN Processor Module —

Technical Dossier

Product Details And Specifications

Bachmann ME200 Series: Comprehensive Module Range and Technical Overview

The Bachmann ME200 series is a modular programmable logic controller (PLC) platform engineered for continuous-process industries including petrochemical refining, nuclear power generation, offshore oil & gas, and large-scale chemical manufacturing. Deployed across installations in Europe, Asia-Pacific, and the Middle East, the ME200 system is characterized by its deterministic real-time execution, IEC 61131-3 compliance, and high-density I/O backplane architecture. Its installed base spans safety-critical applications where mean time between failures (MTBF) and long-term spare parts availability are primary procurement criteria. The ME203/CN is the central processing unit of this platform, responsible for program execution, inter-module communication coordination, and network interface management via the integrated CN (Controller Network) port.

The Evolution of ME200 Series Architecture

The ME200 platform was introduced by Bachmann electronic GmbH (Austria) as a successor to earlier proprietary control architectures, targeting mid-to-large scale automation projects requiring deterministic scan times under 1 ms. The original ME200 rack design established a passive backplane bus with defined slot addressing, allowing hot-swap capability on select I/O modules without process interruption.

Early revisions of the CPU modules (ME201, ME202) operated with limited onboard memory and required external EPROM-based program storage. The ME203 generation introduced integrated flash memory, expanded SRAM, and the CN (Controller Network) communication port, enabling peer-to-peer controller synchronization and redundancy configurations. Subsequent firmware revisions extended Ethernet connectivity options and added support for PROFIBUS-DP master/slave roles directly from the CPU.

As of 2026, the ME200 series is in its mature/end-of-life phase. Bachmann has transitioned its active development roadmap to the MX200 and MC200 platforms. However, the ME200 remains in active service at thousands of installed sites globally, and OEM replacement parts are no longer manufactured in volume. Procurement of ME200 modules now relies primarily on certified aftermarket suppliers and refurbished stock channels. Long-term maintenance contracts for ME200-based systems require a dedicated spare parts inventory strategy.

ME200 Series Full Catalog & Functionalities (SKU List)

CPU / Processor Modules

• ME203/CN: Central processor module with integrated Controller Network (CN) port; IEC 61131-3 runtime; primary CPU for ME200 rack systems.
• ME201: Entry-level CPU module; limited onboard memory; EPROM program storage; early-generation ME200 installations.
• ME202: Mid-range CPU; expanded RAM over ME201; supports basic Ethernet configuration via external adapter.
• ME204: High-performance CPU variant; extended instruction set; supports redundant CPU configurations in critical process applications.
• ME205/CN: Enhanced CN-port CPU; increased scan rate performance; designed for high-density I/O rack configurations exceeding 512 I/O points.

Digital Input (DI) Modules

• ME220/DI16: 16-channel 24 VDC digital input module; sink/source configurable; standard process signal acquisition.
• ME221/DI32: 32-channel high-density digital input; dual-row terminal block; suited for motor control center (MCC) status monitoring.
• ME222/DI16-NAMUR: 16-channel NAMUR-compatible digital input; intrinsically safe signal conditioning for hazardous area field devices.

Digital Output (DO) Modules

• ME230/DO16: 16-channel 24 VDC digital output; transistor sourcing type; relay-driven actuator control.
• ME231/DO8-R: 8-channel relay output module; 250 VAC / 2A per channel; used for solenoid valve and contactor switching.
• ME232/DO32: 32-channel high-density transistor output; compact footprint for large discrete output applications.

Analog Input (AI) Modules

• ME240/AI8: 8-channel analog input; 4–20 mA / 0–10 V selectable; 12-bit resolution; process variable acquisition.
• ME241/AI8-TC: 8-channel thermocouple input module; supports J, K, T, E, R, S, B type thermocouples; cold junction compensation onboard.
• ME242/AI8-RTD: 8-channel RTD input; PT100/PT1000 compatible; 3-wire and 4-wire measurement configurations.

Analog Output (AO) Modules

• ME250/AO4: 4-channel analog output; 4–20 mA; 12-bit DAC; control valve and variable speed drive setpoint transmission.
• ME251/AO8: 8-channel analog output; 0–10 V / 4–20 mA dual-mode; high-channel-density process control loops.

Communication / Network Modules

• ME260/PROFIBUS-DP: PROFIBUS-DP master/slave communication module; up to 12 Mbit/s; field device integration for distributed I/O and drives.
• ME261/MODBUS-TCP: Modbus TCP/IP gateway module; Ethernet port; SCADA and HMI integration for legacy Modbus-based systems.
• ME262/CANopen: CANopen master module; ISO 11898 compliant; motion control and sensor network integration.

Power Supply Modules

• ME210/PS24: 24 VDC rack power supply module; 10A output; primary power source for ME200 backplane and I/O modules.
• ME211/PS24-R: Redundant 24 VDC power supply; hot-swap capable; used in high-availability process control configurations.

Sourcing Hard-to-Find & Obsolete ME200 Series Parts

With the ME200 series in end-of-life status, OEM factory orders for modules such as the ME203/CN, ME204, ME220/DI16, and ME260/PROFIBUS-DP are no longer fulfilled through standard distribution channels. DriveKNMS maintains a dedicated inventory of tested and certified ME200 series modules sourced through controlled aftermarket channels, including decommissioned plant equipment, authorized refurbishment programs, and long-term storage stock.

DriveKNMS provides lifecycle extension support for ME200-based systems including: verified functional testing of all CPU and I/O modules prior to shipment; firmware version matching to ensure compatibility with existing rack configurations; cross-reference identification for modules where original part numbers have been superseded; and emergency same-day dispatch for critical process shutdowns. Customers operating ME200 systems in refineries, power stations, or chemical plants with 10+ year remaining operational horizons are advised to establish a strategic spare parts buffer. DriveKNMS can assist in developing a site-specific ME200 spare parts matrix based on installed rack configurations.

Quality Control for the ME200 Series Range

ME200 series modules present specific test challenges due to their passive backplane bus architecture and CN network communication protocol. DriveKNMS applies the following test procedures to all ME200 inventory:

• Backplane Bus Integrity Test: Each module is seated in a reference ME200 rack and subjected to full backplane communication verification, confirming slot addressing, data bus continuity, and power rail stability at 24 VDC ±5%.
• CPU Functional Execution Test: ME203/CN and all CPU variants are loaded with a standardized IEC 61131-3 test program covering ladder logic, function block, and structured text execution. Scan time consistency is measured across 10,000 cycles.
• CN Port Communication Verification: The Controller Network port on ME203/CN and ME205/CN modules is tested for peer-to-peer frame transmission, error detection, and redundancy switchover timing.
• I/O Channel-Level Calibration: All analog modules (AI and AO) undergo per-channel calibration against NIST-traceable reference instruments. Digital I/O modules are tested for switching threshold accuracy and output current compliance.
• Thermal Stress Screening: Modules are subjected to a 4-hour burn-in cycle at 55°C to identify latent component failures prior to shipment.
• Cosmetic and Connector Inspection: All backplane connectors, terminal blocks, and front-panel indicators are inspected under magnification. Modules with damaged connector pins or corroded contacts are rejected.