NI VME-MXI-2 VMEbus Extender

The NI VME-MXI-2 is a 6U VMEbus extender that extends VMEbus architecture outside a mainframe chassis via MXI-2 cable links. It enables remote access and control of VMEbus instruments while allowing external computers to operate as integrated VMEbus masters. The module supports transparent master and slave operations across A16, A24, and A32 address spaces, with full compatibility for D08, D16, D32, and D64 (VME64) data cycles. Up to 8 VXI or VME chassis can be interconnected via MXIbus cables to function as a single cohesive system.

– Technical Specifications

• Form Factor: 6U, single-slot VMEbus module
• Dimensions: 23.3 × 16.0 cm (9.2 × 6.3 inches)
• Weight: 332 g typical (without DRAM)
• Data Transfer Rates:
– Peak: 33 MB/s
– Sustained: 23 MB/s
– Maximum DMA (D64): 38 MB/s
• Address Space Support: A16 (including dedicated 16 KB VXIbus configuration window), A24, A32
• Bus Cycles: Master and slave operations for A32, A24, A16, D64, D32, D16, D08 (EO) cycles
• DRAM Expansion: Optional dual-ported, up to 64 MB
• Operational Modes: Interlocked and parallel
• Interfaces: Single fully implemented MXI-2 bus connector; standard VMEbus interface

– Key Features

• MXIbus block-mode transfers translate to VMEbus block-mode transfers; automatically generates non-block-mode cycles for unsupported slave devices
• Acts as VMEbus system controller when installed in leftmost slot with automatic Slot 0 detection
• Transparent interrupt forwarding between mainframes
• VMEbus RETRY signal support to resolve deadlock conditions
• VMEbus miscellaneous services, system controller functions, and interrupter functions supported

– Typical Applications

• Remote VMEbus system control and monitoring from external host computers
• Multi-chassis VME/VXI system integration operating as single logical VME domain
• High-performance data acquisition and instrumentation control requiring distributed architecture

– Compatibility & Integration

Full VMEbus compliance including master/slave capability, system controller functions, and miscellaneous services. MXIbus architecture derived from VMEbus enables cable-based extension with preserved bus semantics and integrated block-mode capability.