XYCOM XVME-686 Product Detailed Description

I. Product Overview

XYCOM XVME-686 is a 6U VMEbus single-board computer (SBC) launched by Xycom (now part of Acromag/Xembedded), designed specifically for industrial control, embedded measurement and control, and high-reliability real-time systems. As a classic VME bus processor module, XVME-686 adopts a PC/AT compatible architecture, integrating a processor, memory, graphics, storage, and I/O interfaces. It can provide stable computing and control capabilities in harsh industrial environments and is the preferred core platform for small and medium-sized embedded systems. 

II. Core Architecture and Hardware Configuration

(1) Processor Core

Equipped with Intel 80386SX processor, with a main frequency of 20 MHz, it includes a built-in math coprocessor, compatible with 32-bit PC/AT instruction set, meeting the requirements of industrial control, data acquisition, and basic real-time computing, and suitable for lightweight embedded operating systems and applications.

(2) Memory System

Configured with dual-access DRAM memory, available in three capacities of 1MB, 4MB, and 8MB. The memory has efficient read and write capabilities, supports VME bus and dual-end access with the CPU, enhancing data interaction efficiency; an optional battery-backed SRAM can be selected, saving critical data in case of power loss, enhancing system reliability.

(3) Storage Interface

Built-in IDE hard disk controller + floppy disk controller, capable of directly connecting IDE hard disks and 3.5-inch floppy disks, supporting local system boot and data storage; compatible with DOC (DiskOnChip) flash drives, suitable for high-stability scenarios without mechanical moving parts, meeting long-term operation requirements.

(4) Graphics Display

Integrated standard VGA graphics controller, equipped with video memory, supporting VGA display output, capable of directly connecting industrial displays and touch screens, with resolution adapted to common industrial specifications, meeting human-machine interface (HMI) display and operation requirements, suitable for industrial site visualization control scenarios.

(5) Bus Interface

VMEbus bus: complies with VME64 standard, supports A16/A24 address space, 32-bit data transmission, compatible with multi-master/slave mode, has BLT block transmission capability, suitable for multi-module collaborative work in VME bus systems, ensuring stable data throughput.

VME interrupt: supports 7 levels of VME interrupts (I1-I7), programmable setting of interrupt priority, suitable for multi-task real-time scheduling, quickly responding to external device interrupt requests.

(6) I/O Interface

Serial ports: 2 DB-9 interfaces RS-232C serial ports, 16550 compatible, adjustable baud rate, capable of connecting sensors, Modbus modules, serial printers, etc. as external devices.

Parallel ports: 1 DB-25 interface ECP/EPP compatible parallel port, suitable for parallel printers, data acquisition cards, etc. as parallel devices.

Keyboard interface: 1 DIN-5 keyboard interface, supporting PS/2 keyboard direct connection, suitable for industrial site operation input.

Front panel indicator lights: integrated power, operation, and fault LED indicators, real-time display of module working status, facilitating on-site debugging and fault troubleshooting.

(7) Power Supply and Power Consumption

Uses VME bus power supply, supporting +5V, ±12V input, typical power consumption ≤ 12W, low-power design reduces heat dissipation pressure, suitable for fanless embedded scenarios, reducing system complexity and fault points.

(8) Physical Specifications

Form: 6U single-slot VME module, occupying 1 slot of the chassis, compatible with standard 6U VME chassis P1 connector.

Size: 165mm × 25mm × 115mm (length × width × height), standard VME module size, compatible with mainstream chassis installation.

Weight: approximately 180g, lightweight design, facilitating installation and maintenance, suitable for various chassis layouts. Storage temperature: -55℃ to +85℃. There is no risk of damage during long-term storage and transportation, ensuring the reliability of spare parts storage.

(II) Protection and Anti-interference

Protection level: Front panel IP65, dust-proof and splash-proof, suitable for harsh industrial environments such as damp, dusty, and oily conditions.

Anti-vibration / Impact: Military-grade reinforced design, capable of withstanding vibration frequencies of 5 to 2000Hz and acceleration of 10g, and shock acceleration of 50g, suitable for scenarios with intense vibration such as machine tools, vehicles, and wind power.

Electromagnetic Compatibility (EMC): Compliant with IEC 61000-6-2/4 standards, with anti-static and anti-electromagnetic interference capabilities, suitable for industrial environments with strong electromagnetic interference (such as frequency converters and high-voltage equipment).

(III) Hardware Reliability

All-solid-state design: Core components have no mechanical moving parts, reducing failure points, and supporting long-term continuous operation (MTBF ≥ 100,000 hours).

Hardware watchdog: Built-in independent watchdog circuit, automatically resets when the system freezes, ensuring continuous operation of the system and reducing the risk of downtime.

Battery backup: Supports CMOS RAM battery backup, allowing long-term preservation of system configurations and key parameters after power loss, avoiding data loss.

Four. Core Functions and Features

(1) PC/AT Compatibility Ecosystem

Fully compatible with PC/AT architecture, supporting MS-DOS, Windows 3.x/95 (reduced version), embedded Linux, VxWorks, etc., allowing direct operation of mature development tools and applications on PC ends, significantly reducing the cost and cycle of secondary development.

(2) Compact Single-slot Design

6U single-slot specification, occupying only 1 VME slot, saving chassis space, suitable for compact embedded systems, facilitating multi-module combination layout, and flexibly adapting to different scale control requirements.

(3) Rich Native I/O

Integrated serial ports, parallel ports, VGA, keyboard interfaces, without the need for additional expansion modules to meet basic peripheral connection requirements, ready to use out of the box, simplifying the system architecture, and improving deployment efficiency.

(4) Real-time Multi-task Processing

VME bus + 7-level interrupt mechanism, capable of microsecond-level real-time response, suitable for scenarios with high real-time requirements such as industrial control, data acquisition, and equipment monitoring, ensuring timely execution of control instructions.

(5) Long Lifecycle Support

Xycom (Acromag) provides long-term technical support and spare parts supply, with a product lifecycle of up to 15 years or more, suitable for the long service cycle requirements of industrial equipment, avoiding system upgrade and replacement costs caused by product discontinuation.

Five. Typical Application Scenarios

Industrial Automation: Production line control, PLC replacement system, equipment monitoring unit, small DCS distributed control system.

Embedded Measurement and Control: Data acquisition system, instrument control, environmental monitoring equipment, laboratory automation device.

Military / Aviation: Vehicle measurement and control, onboard auxiliary control, radar data preprocessing, military communication terminal.

Transportation / Energy: Rail transit vehicle control, wind power / photovoltaic on-site control unit, smart grid monitoring equipment.

Medical Equipment: Medical imaging equipment control, automated detection instrument, critical control board of intensive care equipment.

Six. Selection and Adaptation Instructions

(1) Model Distinction

XVME-686: Standard version, 20MHz 80386SX, 4MB DRAM, industrial temperature (-20℃~70℃).

XVME-686/8: High-capacity memory version, 8MB DRAM, suitable for large data processing requirements.

XVME-686/W: Wide-temperature version, -40℃~85℃ operating temperature, enhanced EMC protection. Optional items: Battery backup SRAM module, DOC flash drive, heat dissipation component.

(II) Compatible chassis

Compatible with standard 6U VME chassis (such as VME64 chassis), requires 1 single-slot, supports P1 connector (data / power), no need for P2 expansion connector, compatible with basic VME system.

(III) Operating system compatibility

Desktop simplified system: MS-DOS, Windows 3.x, Windows 95 (embedded simplified version).

Embedded system: Embedded Linux 2.0/2.4, VxWorks 5.x, QNX 4.x, pSOS.

VIII. Maintenance and Precautions

Before installation, the power supply of the chassis must be cut off. Do not perform hot swapping. Avoid damage to the module connector and chips due to sudden current shock; during installation, gently insert and push to ensure that the P1 connector is fully engaged.

Regularly check the status of the front panel indicator lights. If the fault light is constantly on, the power supply, peripheral connections, and module hardware status must be checked to avoid running with faults.

The battery backup module is recommended to be replaced every 3 years to prevent battery aging and leakage from damaging the circuit board, and to avoid loss of configuration data after power failure.

During long-term operation, ensure good ventilation of the chassis, regularly clean the dust on the module surface and the chassis heat dissipation channels to avoid frequency reduction or system freeze due to high temperature.

Avoid using in strong corrosive and strong radiation environments. If necessary, add a protective shell or shielding device to extend the module service life.