R312B MELSEC iQ-R 12-Slot Main Base Unit | Mitsubishi

The Original New Mitsubishi R312B is a 12-slot main base unit (backplane/rack) for the MELSEC iQ-R series programmable controller platform. It provides the physical and electrical foundation for assembling a modular control system, accommodating one power supply module, one CPU module, and up to twelve I/O or intelligent function modules. The R312B is a standard type main base unit designed for surface/panel mounting using M4 screw holes, with optional DIN rail mounting support via the R6DIN1 adapter (sold separately). As the central chassis of an iQ-R system, it enables high-speed backplane communication between modules and allows expansion with up to seven extension base units for large-scale automation applications.

Core Engineering Highlights:
12 total slots (1 power supply + 1 CPU + 12 I/O/intelligent module slots) | 5 V DC internal current consumption: 0.88 A | Dimensions (H × W × D): 101 × 439 × 32.5 mm | Weight: approx. 0.72 kg | Mounting: surface/panel mount (M4 screw holes or ø4.5 mm holes) | Optional DIN rail adapter: R6DIN1 (sold separately) | Expandable with up to 7 extension base units

Key Features:

• Original New Mitsubishi R312B main base unit

• 12 slots: 1 dedicated power supply slot (leftmost), 1 CPU slot (second from left), and 12 slots for I/O and intelligent function modules

• Rigid metal base with M4 mounting holes (or ø4.5 mm holes for M4 screws) for secure surface/panel installation

• Supports optional DIN rail mounting with the R6DIN1 adapter (sold separately)

• High-speed iQ-R backplane bus for low-latency communication between modules

• Expandable with up to 7 extension base units via RC series extension cables

• Compatible with the full range of MELSEC iQ-R series modules

• 439 mm width for high-density module configurations

• RoHS compliant, CE, UL/cUL, UKCA approved

• Shipping approvals: ABS, BV, DNV GL, LR, NK, RINA

Applications:

• Central chassis for large-scale MELSEC iQ-R series PLC systems

• Hosting power supply, CPU, I/O, and intelligent function modules

• Multi-CPU configurations for high-speed motion control and sequence control

• Large-scale machine automation and process control

• Factory automation and production line control panels

• Distributed I/O architectures with extension base units

• Industrial control panels requiring maximum module density

Technical Specifications:

System Compatibility:

• Compatible with all Mitsubishi MELSEC iQ-R series power supply modules (R61P, R62P, R63P, R64P, R61SP, R64RP)

• Compatible with all iQ-R series CPU modules (R00CPU, R01CPU, R02CPU, R04CPU, R08CPU, R16CPU, R32CPU, R64CPU, R120CPU, and Motion CPU modules)

• Compatible with the full range of iQ-R series I/O modules, intelligent function modules, and communication modules

• Expandable with iQ-R series extension base units (R65B, R68B, R612B) using RC series extension cables

• Configured via GX Works3 engineering software

Related Products:

• R33B – 3-slot main base unit (lower slot count)

• R35B – 5-slot main base unit (mid slot count)

• R38B – 8-slot main base unit (mid slot count)

• R65B – 5-slot extension base unit with power supply slot

• R68B – 8-slot extension base unit with power supply slot

• R612B – 12-slot extension base unit with power supply slot

• R61P – Power supply module, 100–240 V AC input, 5 V DC 6.5 A output

• R04CPU – iQ-R series CPU module, 40K steps program capacity

• RX40C7 – 16-point digital input module, 24 V DC

• R6DIN1 – DIN rail mounting adapter for R312B (sold separately)

• GX Works3 – Engineering software for MELSEC iQ-R series

PLC ERA is an independent industrial automation distributor supplying genuine Original New products through established global supply channels. All products are factory sealed when applicable and undergo quality inspection prior to shipment. Mitsubishi, MELSEC, and MELSEC iQ-R are trademarks of Mitsubishi Electric Corporation.