XYCOM XVME-976 PC board computer

Core positioning and purpose

XVME-976 is essentially a single board computer designed to be inserted into a slot in a VMEbus chassis as the main controller or processing core for the entire industrial control or embedded system.

It is mainly used in environments that require extremely high reliability, robustness, and real-time performance, such as:

Factory workshop (PLC control, data acquisition)

Process Control (Chemical, Energy)

Military and Aerospace Systems

Transportation system

Medical imaging equipment

Key technologies and hardware specifications

As a typical "PC board computer", it integrates the core components of PC compatible machines of that era, but presented in the form of industrial grade modules:

Processor: Typically equipped with Intel 80486DX/DX2 or AMD 486 series microprocessors. This is the foundation of its' PC compatibility ', allowing it to run DOS, Unix like real-time operating systems (such as VxWorks, QNX), or early Windows.

Bus interface: VMEbus. This is its most important feature. VMEbus is a robust and highly reliable non multiplexed parallel bus that supports multiple masters and distributed processing, making it ideal for industrial applications.

Onboard memory: typically equipped with DRAM (ranging from a few MB to tens of MB) and ROM/Flash for BIOS/bootloader.

I/O interface: The board is equipped with standard PC peripheral device interfaces, allowing it to connect common devices:

Ethernet: 10BASE-T or 10BASE2 (coaxial thin cable), used for network connection.

Serial port: Multiple RS-232/422/485 serial ports used to connect terminals, modems, or industrial equipment.

Parallel port: Typically a Centronics parallel port used to connect printers or other devices.

Keyboard/Mouse Interface: PS/2 or AT interface.

Disk interface: IDE interface, used to connect hard drives or solid-state electronic drives.

Display interface: It may be a standalone VGA controller or require a separate VME display module.

Real time clock/calendar: equipped with battery backup to ensure that system time is not lost in case of power failure.

Watchdog timer: a critical industrial function. If the software hangs due to a malfunction, the watchdog will automatically reset the system to ensure maximum availability.

System composition and working mode

XVME-976 itself is just a module. A complete system requires:

VMEbus chassis/backplane: provides power, physical support, and bus connections.

Power supply: Industrial grade power supply, usually installed inside the chassis.

Peripheral modules: Insert different VME modules into other slots of the chassis according to requirements, such as:

Digital I/O module: connects switches, sensors, and relays.

Analog I/O module: processes voltage/current signals.

Motion control module: controls the motor.

Communication module: Supports fieldbus such as Profibus and CAN.

Display module: Provides graphical display output.

Operating System and Software: Run systems such as MS-DOS, iRMX, VxWorks, QNX, Lynx, etc., and develop specialized control applications.