Motorola MVME374 Intelligent VMEbus Ethernet Controller Board

Motorola MVME374 | Intelligent VMEbus Ethernet Controller Board

The Motorola MVME374 is a high-performance, intelligent Ethernet controller board designed for the VMEbus (IEEE 1014) architecture.

It functions as a dedicated communications processor, offloading network protocol management from the main system CPU to improve overall real-time system throughput.

By integrating a dedicated microprocessor and shared onboard memory, the MVME374 provides a stable and efficient gateway for VME-based systems to connect to local area networks (LAN).

Technical Parameter Table

Product Advantages and Features

Intelligent Processing: Features its own 68K series MPU, allowing it to handle complex Ethernet framing and protocol stacks without taxing the system’s primary processor.

Shared Memory Architecture: Onboard DRAM is accessible by both the local processor and the VMEbus, facilitating high-speed data exchange via DMA (Direct Memory Access).

VMEbus Standard Compliance: Fully compatible with the Eurocard format, making it easy to integrate into existing VME racks from Motorola, Emerson, or other manufacturers.

Field-Proven Reliability: Designed for long-lifecycle industrial and military applications where deterministic communication is critical.

Diagnostic Tools: The integrated 374Bug firmware allows for extensive local and remote diagnostics, simplifying system troubleshooting.

Application Cases

Distributed Control Systems (DCS): Acts as the primary communication link for industrial plants requiring synchronized data exchange between multiple VME racks.

Steel Works & Heavy Manufacturing: High-reliability networking in environments with high electromagnetic interference.

Shipboard Control Systems: Used in maritime automation for engine room monitoring and navigation data distribution.

Legacy System Support: Serving as a vital replacement part for aging Motorola 68K-based industrial workstations and servers.

Other Models in the Same Series

MVME374-1: The standard revised version featuring enhanced memory options.

MVME376: A high-performance successor with advanced Ethernet controller ASICs.

MVME147: A full single-board computer that often includes integrated Ethernet similar to the 374’s logic.

MVME712B: Transition module used to provide physical SCSI and Ethernet ports for the backplane.

Installation and Maintenance

Pre-Installation: Check jumper headers (such as J1 for software-readable settings) to match your system’s VMEbus memory map.

ESD Protection: Always wear an anti-static wrist strap. The MC68020 and BIOS chips are highly sensitive to static discharge.

Mounting: Ensure the board is properly aligned with the VME P1 and P2 connectors. Use the front-panel ejector handles to seat the board firmly before tightening the retention screws.

Maintenance: Monitor the “Fail” LED during boot-up. A persistent red LED typically indicates a self-test failure in the onboard RAM or BIOS.

Cleaning: Periodically inspect the 15-pin AUI port for dust; use compressed air if necessary to ensure a clean connection to the transceiver.

Unique Product Description

The Motorola MVME374 is more than just a network card; it is a dedicated “communications officer” for the VMEbus.

While modern Ethernet controllers are often integrated into a single chip, the MVME374’s discrete design with a dedicated 68020 processor ensures that even under heavy network loads

your core industrial processes remain uninterrupted. It remains a cornerstone for engineers maintaining robust, time-tested infrastructure that demands absolute reliability over raw speed.