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

The Mitsubishi Electric MELSEC iQ‑R series main base unit houses the power supply and CPU. Its 12 I/O slots support high‑density module configurations in large‑scale automation systems. The iQ‑R backplane bus ensures high‑speed data transfer between modules. Panel mounting via M4 screws (ø4.5 mm holes) or DIN rail mounting using the optional R6DIN1 adapter. Compatible with all iQ‑R series power supply, CPU, I/O and intelligent function modules.

Applications:

• Main chassis for MELSEC iQ‑R PLC systems with up to 12 I/O modules

• Central rack for high‑density industrial control cabinets

• Hosting high‑speed CPU modules and intelligent function modules in factory automation

• Multi‑CPU configuration requiring expanded I/O capacity

Core Specifications:

• Number of I/O slots: 12

• Power supply slot: 1 (leftmost slot)

• CPU slot: 1 (second slot from left)

• Slots 2 – 11: I/O modules and intelligent function modules

• 5 V DC internal current consumption: 0.88 A (supplied by power supply module)

• Dimensions (W × H × D): 439 mm × 101 mm × 32.5 mm

• Mounting hole size: M4 screw hole or ø4.5 mm hole (for M4 screw)

• Weight: approx. 0.72 kg

System Integration:

• Main base unit belongs to the Mitsubishi Electric MELSEC iQ‑R series.

• A power supply module (e.g., R61P AC or R63P DC) must be installed in the leftmost slot.

• A CPU module (e.g., R04CPU, R08CPU, R16CPU, R32CPU, R120CPU) must be installed in the second slot from the left.

• Up to 7 extension base units (R65B, R68B, R612B) can be connected via RC series extension cables (0.6 m to 10 m).

• For detailed current consumption calculation and system configuration, refer to the MELSEC iQ‑R Configuration Manual.

Related Products:

• R61P – AC power supply module for iQ‑R series (100‑240 V AC, 5 V/6.5 A)

• R04CPU – CPU module, 4 KB program capacity

• R08CPU – CPU module, 8 KB program capacity

• R35B – 5‑slot main base unit (lower capacity)

• R38B – 8‑slot main base unit (mid capacity)

• R312B – 12‑slot main base unit (current model)