R38B MELSEC iQ-R 8-Slot Main Base Unit | Mitsubishi

The Original New Mitsubishi R38B is an 8-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 six I/O or intelligent function modules. The R38B features a rigid metal construction with M4 mounting holes for surface/panel installation and supports optional DIN rail mounting via the R6DIN1 adapter (sold separately). As the central chassis of an iQ-R system, it enables high-speed backplane communication between modules, supports multi-CPU configurations, and allows expansion with up to seven extension base units for large-scale automation applications.

Core Engineering Highlights:
8 total slots (1 power supply + 1 CPU + 6 I/O module slots) | 5 V DC internal current consumption: 0.71 A | Dimensions (H × W × D): 101 × 328 × 32.5 mm | Weight: approx. 0.55 kg | Mounting: panel/surface mount (M4 screw holes) | Optional DIN rail adapter: R6DIN1 (sold separately) | Supports up to 4 CPU modules | Expandable with up to 7 extension base units

Key Features:

• Original New Mitsubishi R38B main base unit

• 8 slots: 1 dedicated power supply slot (leftmost), 1 CPU slot (second from left), 6 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

• Multi-CPU configuration support (up to 4 CPUs per rack)

• Expandable with up to 7 extension base units via RC series extension cables (0.6 m to 10 m)

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

• Compact 328 mm width for space-efficient panel layout

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

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

Applications:

• Central chassis for 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

• Medium to 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 modular PLC configuration

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

• Multi-CPU configurations supported (up to 4 CPUs per rack)

• 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)

• R312B – 12-slot main base unit (higher slot count)

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

• R68B – 8-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 R38B (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.