Schneider Modicon M340 BMXP342020 Replacement

Overview

The Schneider Electric Modicon M340 series has long served as a modern, reliable powerhouse for medium-to-large-scale industrial automation systems. At the heart of many of these installations is the BMXP342020 Performance Processor. Known for its compact footprint, slot-saving integrated communications, and robust execution speeds, this CPU is a critical component in infrastructure, manufacturing, and process plants globally.

When a BMXP342020 processor fails, or when a facility is undergoing system modernization, choosing the correct replacement path is vital. This guide details the technical specifications of the legacy BMXP342020, outlines direct and next-generation replacement options, highlights critical hardware and software compatibility considerations, and provides a systematic, step-by-step physical replacement procedure.

Legacy Product Information

The BMXP342020 is a high-performance CPU module within the Modicon M340 automation platform. It is engineered to manage complex logic, mathematical formulations, and communication overhead across distributed architectures.

Key Technical Specifications:

• Catalog Number: BMXP342020 (often written as BMX P34 2020)
• Processor Performance: 0.12 microseconds for Boolean instructions, 0.18 microseconds for electrical/numerical multi-bit instructions.
• Memory Capacity: 4096 KB internal RAM (with up to 256 KB for program application structures, 128 KB for data, and 2048 KB for file storage).
• Memory Expansion: Requires the proprietary BMXRMS008MP flash memory card (SD card format) for application program backup, diagnostics, and web server storage.
• Integrated Communication Ports:
  • 1 x RJ45 Ethernet TCP/IP port (10/100 Mbps, auto-negotiating) supporting Modbus TCP and EtherNet/IP (via specific firmware and configuration options).
  • 1 x RJ45 Modbus non-isolated serial link (RS-232/RS-485, up to 115.2 Kbps).
  • 1 x mini-B USB port (primarily for programming, diagnostics, and firmware updates).
• I/O Capacity: Supports a maximum of 1024 discrete inputs/outputs and 256 analog inputs/outputs across up to 4 racks (under local daisy-chaining schemes).
• Lifecycle Status: Active but Mature. While Schneider Electric continues to manufacture and support the M340 line, newer systems are steering toward the Modicon M580 programmable automation controller (PAC) series due to cybersecurity standards and advanced network capabilities. Replacement parts are frequently sourced from specialized suppliers to avoid complete control system rebuilds.

Recommended Replacements

Depending on your facility's budget, downtime tolerance, and long-term automation roadmap, there are three primary paths for replacing a faulty or aging BMXP342020 processor.

Compatibility Considerations

Before procuring a replacement CPU, verify the sub-system environment variables to ensure zero-loss compatibility.

1. Backplane and Slots

The BMXP342020 resides in Slot 00 (immediately adjacent to the Power Supply Module) on a Modicon BMX backplane (such as the BMXXBP0400, BMXXBP0600, BMXXBP0800, or BMXXBP1200).

• Note: The older Modicon Premium or Quantum backplanes are entirely incompatible.
• M580 Note: If upgrading to a BMEP582020 (M580), you must upgrade to an Ethernet backplane (BMEXBP series). Although the M340 discrete and analog I/O modules will physically fit and operate in these BME backplanes, the processor slot itself is different and requires the upgraded bus.

2. Configuration & Programming Software

The Modicon M340 platform is programmed via Unity Pro (v4.0 up to v13.0) or its modern successor, EcoStruxure Control Expert. If replacing like-for-like, standard project backup files (.STX or .ZEF formats) can be downloaded directly into the new processor without software modifications, provided the firmware versions match or the program is recompiled to target the specific firmware of the new unit.

3. Memory Card Retention

The program memory of the M340 is stored in volatile RAM backed up by an internal supercapacitor for state retention, and written non-volatilely to the BMXRMS008MP flash card. When replacing the CPU, you must transfer this card to the new unit. Warning: Standard consumer-grade SD cards will not function and may fault the processor. Always use the original Schneider-branded memory card.

4. Communication Parameters

The Ethernet port on the BMXP342020 is configured either via a static IP defined in the programming project, or via a DHCP/BOOTP server bound to the MAC address of the CPU. If replacing a CPU with a new unit, note that the physical MAC address will change. You must update your network’s DHCP/BOOTP servers with the new MAC address or manually download the IP profile via a mini-USB cable to establish field network communications.

Upgrade Benefits

While swapping with a direct replacement (BMXP342020) minimizes immediate engineering hours, migrating to the next-generation Modicon M580 (BMEP582020) yields several long-term field advantages:

• Cybersecurity (Achilles Level 2): The M580 has robust built-in protection against unauthorized access, firmware alteration, and distributed denial-of-service (DDoS) attacks.
• Execution Speed: Upgrading to the M580 speeds up CPU execution by up to 10x, enabling faster loop times, higher precision, and the capacity for much larger application projects.
• Native Ethernet Backplane: The dual-port Ethernet capabilities of the M580 backplanes allow standard Ethernet/IP and Modbus TCP instruments to connect directly to the rack without requiring external communication modules (such as the BMXNOC0401).

Common Migration Challenges

• Firmware Mismatches: If the replacement BMXP342020 arrives with a newer (or older) firmware than the original program's target compile version, the CPU will reject the program download. You must use the Schneider Loader Utility to flash the CPU to the expected OS version.
• IP Address Loss: Swapping the processor without backing up the configuration files can sever connection links to SCADA systems, HMIs, and remote drop I/O.
• Losing Variable Retention Data: If the PLC loses power complete with a drained super-capacitor, run-time values and calibration offsets stored in volatile %MW registers will revert to initial configuration states. Ensure a valid backup of run-time data is taken before physically disconnecting the old unit.

Step-by-Step Replacement Procedure

Follow these detailed configuration and installation steps to safely swap a faulty BMXP342020 processor:

Phase 1: Software and Program Backup

1. Connect your PC to the running (or partially functioning) CPU via the mini-USB port using EcoStruxure Control Expert.
2. Go online and perform a Save and Upload of the running program.
3. Export the project to a .ZEF format (which includes structural and diagnostic data).
4. Save a backup of the current register variables (.DTX or .DAT file export) to ensure variable parameters match previous operational states.
5. If the CPU is non-responsive, contact your IT/Engineering department to retrieve the latest version-controlled backup file from the engineering workstation repository.

Phase 2: Hardware Isolation and Lockout

1. Switch the target process loop or production line to manual control or a safe state.
2. Turn off the power switch located on the Modicon Power Supply Module (BMXCPSxxxx) on the same backplane.
3. Apply standard Lockout/Tagout (LOTO) protocols at the main breaker feeding power to the control cabinet.
4. Verify using a digital multimeter that no voltage is present on the incoming terminals of the power supply or adjacent field wiring.

Phase 3: Physical Extraction

1. Disconnect the RJ45 Ethernet cable and the Modbus serial cables from the front ports of the CPU. Clearly label the cables to avoid cross-connection during re-installation.
2. Locate the memory card slot cover under the front hinged door. Gently press the BMXRMS008MP flash card in to release it, then pull it straight out. Store it in an ESD-safe bag.
3. Loosen the retention screw at the bottom of the BMXP342020 processor module.
4. Pivot the bottom of the CPU module outward away from the backplane, and lift it upward to unhook the top tabs from the slot chassis.

Phase 4: Installation of the New Processor

1. Inspect the backplane connectors for dust, debris, or bent pins. Clear any obstructions using canned compressed air.
2. Verify that the hardware orientation tabs on the top of the new BMXP342020 align with the slot on the backplane.
3. Hook the top of the CPU module onto the top rail of the backplane.
4. Pivot the module downward until it is firmly flushed against the backplane connector.
5. Re-tighten the lower recovery screw to ensure a ground connection to the backplane chassis. Do not over-torque.
6. Slide the original BMXRMS008MP memory card into the slot until it clicks into position. Close the card slot cover.
7. Reinsert the RJ45 Ethernet and Modbus serial cables into their respective ports.

Phase 5: Power Restoration and Startup

1. Remove LOTO brackets and restore main power.
2. Turn on the switch on the BMXCPSxxxx power supply module.
3. Monitor the processor LED startup sequence:
   • The CARDERR light may blink temporarily while the CPU reads data from the memory card.
   • If the memory card contains the compiled program and is configured to auto-load, the RUN LED should transition to solid green.
   • If the ERR LED flashes, it indicates a configuration mismatch, missing application, or IP address conflict.
4. If communication to HMI/SCADA is not automatically restored, connect via the front mini-USB port and download the saved .ZEF project file using EcoStruxure Control Expert, ensuring all variable data tables are restored.

Frequently Asked Questions

Q: Can I run the M340 BMXP342020 without an SD memory card?

A: No. The BMXP342020 requires the BMXRMS008MP flash card to function. Without the card installed, the processor will lock in a halted state with a fast-blinking CARDERR LED, and you will be unable to run applications.

Q: Does the BMXP342020 support hot-swapping?

A: No. While various I/O and communication modules on the M340 platform support Hot Swap (RJ45 and terminal blocks can be pulled), the central CPU and the Power Supply modules do not. The backplane must be completely powered down before extracting or inserting the CPU.

Q: How do I assign the IP address to a newly replaced processor?

A: You can assign the IP address via the DHCP/BOOTP Server utility integrated into EcoStruxure Control Expert, by matching the hardware MAC address of the new unit, or by downloading the project directly to the CPU via a mini-USB cable which configures the static IP parameters.

Q: What is the differences between BMXP342020 and BMXP342020H?

A: The "H" suffix models denote "Harsh Environment" variants. They are identical in terms of function, layout, programming, and performance, but feature specialized conformal coating to protect against chemical vapor corrosion, high humidity, condensation, and extreme operational temperatures (-25°C to +70°C).

Related Products & Families

To ensure a continuous and robust operating lifespan for your newly replaced Modicon M340, look to retain or stock spare compatible parts:

• Power Supplies: BMXCPS2000, BMXCPS3020, BMXCPS3500 (Provides 24VDC/100-240VAC power distribution limits).
• Memory Modules: BMXRMS008MP (Proprietary Schneider memory flash cards).
• Communication Options: BMXNOC0401 (Ethernet/IP - Modbus TCP Network Module), BMXNOM0200 (2-port Serial Modbus Module).
• Digital I/O: BMXDAI1602 (16-Point 24VAC Discrete Input), BMXDRA1605 (16-Point Relay Output Module).

Need Help?

Whether you are looking for a direct direct-exchange spare or planning a transition toward higher efficiency modernizations, Palm Parts Solution has you covered. We supply a continuous range of new, refurbished, and certified surplus PLC systems, I/O modules, power supplies, and processors—including the Schneider Electric Modicon M340 BMXP342020. Every part supplied by Palm Parts Solution is rigorously tested and shipped with a comprehensive warranty to minimize system downtime. Contact our automation experts today to source your backup hardware or explore custom upgrade paths.