Why the BMXP3420302 Belongs in Your Spares Crib
Downtime hits hard when a processor module fails. The Schneider BMXP3420302 is a Modicon M340 processor module built for plants that need fast logic, flexible I/O, and simple service. From a maintenance engineer’s view, this module earns its place because it combines CANopen and Ethernet connectivity with generous I/O capacity in a compact, rack-mounted package.
What This Processor Module Does
The BMXP3420302 is a processor module for the Modicon M340 automation platform. It supports up to 4 racks and 11 slots, giving you room to grow without swapping controllers. The module handles 1024 discrete I/O in a multi-rack configuration and 704 discrete I/O in a single-rack setup. For analog signals, it manages 256 I/O in multi-rack mode and 66 I/O in single-rack mode. It also provides 36 application-specific channels for programmable loops and motion control, including independent axis CANopen.
Key Technical Specifications
Processing Speed You Can Count On
Execution time per instruction is 0.12 µs for Boolean, 0.17 µs for double-length words, 0.25 µs for single-length words, and 1.16 µs for floating points. The module delivers 6.4 Kinst/ms with 65% Boolean and 35% fixed arithmetic, or 8.1 Kinst/ms at 100% Boolean. System overhead is 0.13 ms for the fast task and 0.7 ms for the master task. That speed matters when your line runs fast and every millisecond of scan time affects throughput.
Memory and Program Structure
Internal RAM totals 4096 kB, split into 256 kB data and 3584 kB program constants and symbols. A supplied memory card (BMXRMS008MP) backs up programs, constants, symbols, and data, and activates the standard web server, class B10. Maximum object areas reach 256 kB of unlocated internal data and 32634 %Mi located internal bits. Default areas include 1024 %MWi internal words, 256 %KWi constant words, and 512 %Mi located internal bits. The application structure supports 1 cyclic/periodic master task, 1 periodic fast task, 64 event tasks, and no auxiliary task.
Communications and I/O
Integrated connections include a USB port at 12 Mbit/s, a CANopen master bus on SUB-D 9 with two twisted shielded pairs from 20 kbit/s to 1 Mbit/s, and an Ethernet TCP/IP RJ45 port on one twisted pair at 10/100 Mbit/s. The processor supports 2 Ethernet communication modules and 4 AS-Interface modules. Embedded services cover CANopen NMT, PDO, SDO, and special functions (SYNC, EMCY, TIME), plus Ethernet bandwidth management, Data Editor, Modbus TCP messaging, Rack Viewer, and SNMP network administration.
Power and Physical Data
Current consumption is 135 mA at 24 V DC, with internal power supply via the rack. Net weight is 0.215 kg (0.474 lb). The module operates from 32…140 °F (0…60 °C) at 10…95% relative humidity without condensation. IP degree of protection is IP20 with TC protective treatment.
Where the BMXP3420302 Fits
Replacement and Upgrade Path
If you run a Modicon M340 platform, this processor drops into existing racks and reuses your I/O cards. That means less rewiring and faster commissioning during a planned outage. Keep a spare on the shelf and you cut mean time to repair from days to hours.
Discrete-Heavy Production Lines
Packaging, assembly, and material handling cells often need hundreds of discrete points. With 1024 discrete I/O in multi-rack mode, one BMXP3420302 can supervise an entire cell while leaving slots open for future expansion.
Process Skids with Analog Loops
Water treatment, dosing, and mixing skids rely on analog measurement. The 256 analog I/O capacity in multi-rack mode supports those loops, while the 36 application-specific channels handle programmable loops and motion control.
Installation and Setup Notes
Mount the module in a Modicon M340 rack and confirm the rack backplane supplies internal power. Connect the USB port for local programming, the RJ45 port for Ethernet TCP/IP, and the SUB-D 9 for CANopen. Verify the status LEDs after power-up: green RUN, ETH ACT, ETH STS, and CAN RUN indicate normal operation. Red LEDs for ERR, I/O, CAN ERR, and CARD ERR signal faults that need attention. Yellow SER COM shows Modbus activity. The module carries CE marking and certifications including UL, CSA, RCM, EAC, and Merchant Navy, and meets standards EN 61131-2, EN/IEC 61010-2-201, UL 61010-2-201, CSA C22.2 No 61010-2-201, IACS E10, EN/IEC 61000-6-5, and EN/IEC 61850-3. It is rated for hazardous location class I division 2.
Maintenance and Reliability
From a service perspective, this module is straightforward. Inspect the rack and connections periodically. Check that ambient temperature stays within 32…140 °F (0…60 °C) and humidity stays at 10…95% without condensation. Keep the IP20 enclosure free of dust and moisture. Watch the CARD ERR LED, since the supplied memory card (BMXRMS008MP) holds program backups. Replace the card during scheduled downtime if it shows faults. Because the module consumes only 135 mA at 24 V DC, it runs cool and puts less stress on the rack power supply. That low current draw supports long service life and lower energy cost over the asset’s life.
Compatibility and Integration
The BMXP3420302 works within the Modicon M340 automation platform and supports CANopen and Transparent Ready concepts. It links to CANopen M20 DS 301 V4.02, DS 303-2, and DS 405 devices through daisy-chaining or tap junctions using CSMA/CA. Up to 63 server devices can sit on the CANopen network. Segment device counts range from 0…16 at 672.6 ft (205 m), 0…32 at 607.0 ft (185 m), and 0…64 at 524.9 ft (160 m). Ethernet TCP/IP supports 10BASE-T/100BASE-TX at 10/100 Mbit/s. CANopen transmission rates and distances include 1 Mbit/s up to 65.6 ft (20 m), 500 kbit/s up to 328.08 ft (100 m), 250 kbit/s up to 820.2 ft (250 m), 125 kbit/s up to 1640.4 ft (500 m), 50 kbit/s up to 3280.8 ft (1000 m), and 20 kbit/s up to 8202.10 ft (2500 m).
Selection Checklist Before You Buy
Confirm your rack count and slot needs match the 4-rack, 11-slot capacity. Check that your I/O count fits within 1024 discrete and 256 analog in multi-rack mode. Verify your network uses CANopen or Ethernet TCP/IP. Make sure your panel maintains the operating temperature and humidity range. If you need a trusted source, SpareTechPLC supplies industrial automation parts and news for maintenance teams. Please verify current lifecycle status and availability with SpareTechPLC before ordering.
Frequently Asked Questions
What is the execution time of the BMXP3420302 for Boolean instructions?
It executes Boolean instructions in 0.12 µs, double-length words in 0.17 µs, single-length words in 0.25 µs, and floating points in 1.16 µs.
How much discrete I/O can this processor handle?
It supports 1024 discrete I/O in a multi-rack configuration and 704 discrete I/O in a single-rack configuration.
What communication ports come integrated?
It includes a USB port at 12 Mbit/s, a CANopen master bus on SUB-D 9, and an Ethernet TCP/IP RJ45 port at 10/100 Mbit/s.
What is the current consumption of the BMXP3420302?
It draws 135 mA at 24 V DC and receives internal power supply via the rack.
What memory card ships with this module?
A supplied memory card (BMXRMS008MP) backs up programs, constants, symbols, and data, and activates the standard web server, class B10.
