Modicon M340 & X80 Buying Guide

Bottom line: the M340 decision is a slot-and-power calculation, not a processor speed contest. Choose the rack first, subtract the power supply and CPU positions, then pick the BMXP34 processor whose memory and ports match the modules you can actually fit.

The PLC Source PRO catalog holds 38 M340 and X80 items, covering processors, power supplies, racks, discrete and analog I/O, Ethernet modules and memory cards. Every SKU below links to a live product page. For the full brand view, see the Schneider Electric collection; for a slot-by-slot check, use the contact page.

How do you choose an M340 processor and rack combination?

Fix the rack size first, because slot positions are shared by the power supply, the processor and the I/O modules. Then choose the BMXP34 that covers your discrete and analog capacity, and only then add Ethernet or CANopen. Buying the largest processor before counting slots usually wastes money and still leaves modules without a position.

Three datasheet facts drive most M340 configurations:

• Capacity: BMXP341000H supports 512 discrete I/O in a single-rack configuration; BMXP342000, BMXP342020 and BMXP3420302 support 1,024 discrete I/O and 256 analog I/O across multiple racks.
• Power budget: BMXCPS2000 provides 8.3 W at 3.3 V for logic, 16.8 W at 24 V for I/O and 10.8 W at 24 V for sensors; BMXCPS4002S raises this to 15 W and 40 W.
• Slot count: BMXXBP0600 has 6 slots and BMXXBP1200 has 12 slots, with the power supply and processor occupying positions inside that count.

Which M340 selection dimensions actually change the part number?

Dimension	What changes across the range	Buying consequence
Processor capacity	512 I/O on BMXP341000H; 1,024 discrete and 256 analog on the BMXP342 series	Small machines can stay on BMXP341000H without losing expansion room
Program memory	2,048 kB on BMXP341000H; 4,096 kB on BMXP342000, BMXP342020 and BMXP3420302	Data logging and recipe handling consume the difference quickly
Ports	Serial and USB on BMXP342000; Ethernet on BMXP342020; Ethernet, CANopen and USB on BMXP3420302	Choose by the fieldbus on the machine, not by the highest model number
Rack size	6 slots (BMXXBP0600) versus 12 slots (BMXXBP1200)	Count the power supply and CPU as slot users before ordering I/O
Power supply	BMXCPS2000 versus BMXCPS4002S with roughly double the 3.3 V and 24 V output	Heavy 24 V sensor loads need the 4002S, not a second 2000
Output type	24 VDC solid state (BMXDDO1602), AC triac (BMXDAO1605), relay (BMXDRA1605)	Relay outputs isolate the PLC from the load but switch more slowly
Memory card	BMXRMS008MP, 8 MB SD flash, listed for BMXP342010, BMXP342000, BMXP341000, BMXP342030 and BMXP342020	Order the card with the CPU, not after commissioning

Which M340 build fits your machine?

• If the machine has fewer than 512 I/O points: BMXP341000H with a BMXXBP0600 rack and BMXCPS2000. This is the lowest-cost configuration that still leaves room for a communication module.
• If you need Ethernet and 1,024 points: BMXP342020 with a BMXXBP1200 rack and BMXCPS2000; add a second supply only when the 24 V sensor load exceeds one rack's power budget.
• If the machine runs CANopen drives: BMXP3420302 provides Ethernet, CANopen and USB on the processor, avoiding a separate CANopen module.
• If the panel has high 24 V sensor current: BMXCPS4002S delivers 15 W at 3.3 V and 40 W at 24 V, which is the practical upgrade before adding an external supply.
• If the field devices are 110 VAC: BMXDAI1604 takes 16 isolated 100–120 VAC inputs, and BMXDAO1605 switches 16 triac outputs at 100–240 VAC.

Which M340 and X80 SKUs are in the PLC Source PRO catalog?

All 15 links below returned HTTP 200 on 7 November 2026. Specifications are the datasheet values published on each product page; confirm the rack slot drawing before ordering a full bill of materials.

Model	Function	Key specification	Product page
BMXP341000H	M340 processor	512 I/O, 2,048 kB RAM, 72 mA at 24 VDC	View BMXP341000H
BMXP342000	M340 processor	1,024 I/O, 4,096 kB RAM, 2 serial RJ45 and USB	View BMXP342000
BMXP342020	M340 processor	1,024 I/O, 4,096 kB RAM, Ethernet 10/100	View BMXP342020
BMXP3420302	M340 processor	1,024 I/O, 4,096 kB RAM, Ethernet, CANopen and USB	View BMXP3420302
BMXCPS2000	Power supply	100–240 VAC input, 8.3 W at 3.3 V, 16.8 W at 24 V	View BMXCPS2000
BMXCPS4002S	Power supply	100–240 VAC input, 15 W at 3.3 V, 40 W at 24 V	View BMXCPS4002S
BMXXBP0600	6-slot backplane	6 slots, 1.68 W, panel mount	View BMXXBP0600
BMXXBP1200	12-slot backplane	12 slots, 0.74 W, IP20	View BMXXBP1200
BMXDDM16022	Mixed discrete I/O	8 inputs and 8 solid-state outputs, 24 VDC, 0.625 A per output	View BMXDDM16022
BMXDAI1604	AC discrete input	16 isolated inputs, 100–120 VAC	View BMXDAI1604
BMXDAO1605	AC discrete output	16 triac outputs, 100–240 VAC, 0.6 A per channel	View BMXDAO1605
BMXDDO1602	DC discrete output	16 outputs, 24 VDC, 0.625 A per channel, 10 A per module	View BMXDDO1602
BMXDRA1605	Relay output	16 normally open relays, 24–240 VAC / 24–48 VDC, 2 A	View BMXDRA1605
BMXAMI0410	Analog input	4 channels, 24-bit ADC, current and voltage ranges	View BMXAMI0410
BMXNOE0110	Ethernet module	1 RJ45 10/100 Mbit/s, Modbus TCP, web server	View BMXNOE0110

Which M340 and X80 parts are interchangeable?

• Processors: BMXP342000, BMXP342020 and BMXP3420302 share the same 4,096 kB memory and 1,024-point capacity, but differ in ports. They fit the same rack and can be exchanged when the port mix is acceptable.
• Racks: BMXXBP0600 and BMXXBP1200 are not interchangeable in a panel layout. The 12-slot rack needs a different cut-out and changes the power dissipation inside the enclosure.
• Power supplies: BMXCPS4002S can replace BMXCPS2000 where the 24 V load exceeds the smaller unit, but the higher output also changes heat dissipation. Verify enclosure temperature.
• I/O modules: all X80 I/O listed here fits an M340 rack, but not a Quantum 140 rack. The backplane connector is different and there is no passive adaptor in this catalog.
• Memory cards: BMXRMS008MP is listed for BMXP341000, BMXP342000, BMXP342010, BMXP342020 and BMXP342030. Do not assume it fits every BMXP34 variant without checking the CPU reference.
• Ethernet: BMXNOE0110 is a network module, not a processor. Adding it does not upgrade a BMXP341000H to 1,024-point capacity; processor capacity is fixed by the CPU.

Frequently asked questions

What is the difference between BMXP341000H and BMXP342020?

BMXP341000H supports 512 discrete I/O with 2,048 kB of internal RAM and no Ethernet port. BMXP342020 supports 1,024 discrete and 256 analog I/O with 4,096 kB of RAM and an Ethernet RJ45 port. The BMXP342020 is the better fit when the machine needs network access and more than 512 points.

How many I/O modules fit on a BMXXBP0600 rack?

The rack has six slot positions, and the power supply and processor occupy positions within that count. In practice, plan the slot allocation on the rack drawing before ordering modules; the exact split between power supply, CPU and I/O positions depends on the rack reference and the modules selected. If the count is tight, move to BMXXBP1200 rather than add a second rack.

Can I use Quantum 140 I/O modules in an M340 rack?

No. Quantum 140 modules use the Quantum backplane and do not fit X80 racks. Conversely, BMX I/O modules do not fit a Quantum rack. Retaining Quantum I/O on a newer architecture requires an Ethernet RIO drop adaptor such as 140CRA31908, not a passive mechanical adaptor.

Does the BMXRMS008MP memory card fit every M340 processor?

No. The datasheet lists compatibility with BMXP341000, BMXP342000, BMXP342010, BMXP342020 and BMXP342030. Check the exact CPU reference before ordering the card, especially for H and CL variants, and confirm whether the card is required for firmware updates or only for program and data storage.

Need a slot and power budget check?

Send your module list, enclosure temperature and 24 V load to the PLC Source PRO contact page. We will confirm rack positions, power supply headroom and CPU capacity against the datasheets. For larger systems, see the Modicon M580 buying guide; for the older platform, see the Quantum 140 buying guide.