ModBlox7 Overview

Family of Specifications

ModBlox7 is a first-of-its-kind open standard for interoperable box PCs. Designed for heavy industry, the standard defines modular units that conform to the 7HP footprint. Modules can be connected together and mounted without a backplane, streamlining solution design and deployment. Ratified in 2024, ModBlox7 is supported by over a dozen companies worldwide.

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Introduction to ModBlox7

The goal of ModBlox7 is to reduce cost and accelerate time to market for organizations looking to extend compute intelligence into harsh, demanding environments. It provides a processor-agnostic, off-the-shelf architecture for building industrial box PCs while remaining extensible and modifiable to meet the needs of various industry use cases.

ModBlox7 can be adopted in many use cases.

ModBlox7 defines three primary types of units: a Central Processing Unit (CPU), a Power Supply Unit (PSU), and I/O Units (IOU). Up to 12 of the units can be interconnected without the need for backplanes or shelf controllers. By removing these expensive components and simplifying the system design, ModBlox7 enables the creation of price-competitive systems even at low volumes.

ModBlox7 is designed for edge computing, data acquisition, communication, and control use cases in transportation, automation, avionics, defense, medical, agriculture, and other demanding markets. A multi-vendor supplier ecosystem helps control costs and ensures product availability over the long lifecycles of deployments in these domains.

System Architecture & Form Factors

ModBlox7 mechanics are based on multiple units that are assembled into a system. The space for a unit is called a slot. Each slot is equivalent to one-twelfth of a standard 19″ rack (about 1.4″), i.e., 7 Horizontal Pitch (7HP). A system may have up to 12 slots (84 HP). Each unit may occupy a single slot or be extended in 7HP increments to 14 HP, 21 HP, etc., and remain compatible with the specification.

A ModBlox7 system may contain up to 12 slots.

A complete system consists of:

  • A housing derived from IEC 60297-3-100 and IEC 60297-3-100
  • One or two Power Supply Units (PSU)
  • One or two Central Processing units (CPU)
  • Up to four PCI Express Gen 2-4-based Input Output Units (IOU)
  • Up to eight USB 2.0/3.0-based Input Output Units (IOU)

Configurations with multiple CPUs or PSUs are intended for redundancy in high-availability or safety-critical applications.

Typical System Configurations

A typical ModBlox7 base system consists of a PSU, a CPU, and at least one IOU. Connections between the CPU and IOUs may be made with PCI Express or/and USB, depending on the functionality and data throughput required.

ModBlox7 systems may use a mix of PCIe and USB for internal connections.

In redundant systems, the CPU and PSU are doubled. Critical IOUs can be shared by the CPUs, while other IOUs can be controlled independently by each CPU. The number of shared IOUs is limited to two units if USB3 is used, four units if PCIe is used, or eight units if USB2 is used.

Redundant systems may use a mix of shared and independent IOUs.

Flexible Housing and Mounting

ModBlox7 is designed for flexible mounting with minimal accessory components. Systems may be installed on walls, DIN rails, or inserted in a 19” sub-rack.

To support this flexibility, the exterior mechanical housing is loosely defined. Each unit has a fixed height and depth that leaves space for requisite components. These include:

  • Up to three PCBs.Separation between the base PCB and its expansion units is made to accommodate the front-panel I/O and support cooling. The PCB may be designed using standard system-on-modules like COM Express®.
  • Conduction cooling.The back of the case is optimized for conduction cooling, optionally with a heatsink. Neither the case materials nor the heatsink design are specified, allowing designers to optimize for their application requirements.
  • Front-panel I/O.The I/O interfaces are undefined, leaving room for manufacturers to customize external connectivity.

ModBlox7 defines a flexible architecture.

Coplanar board-to-board connectors couple each unit to its neighbor and route defined I/O interfaces to the next board. Units may be daisy-chained in normal or redundant configurations over standard internal PCI Express or USB interfaces supplied on the PCBs within each unit.

Power Delivery Architecture

The ModBlox7 PSU converts external supply voltages into 12 Volts internally. Power is supplied to CPUs through the electrical connection made via wire-to-board connectors between the PSU and CPU. CPU power is supplied to the nearest IOU via a coplanar board-to-board connector, and IOU power supplies are daisy-chained via unit-to-unit board-to-board connectors.

ModBlox7 power supply architecture.

Contributing Organizations