User manual

Chapter 1 Introduction
VXI-MXI-2 User Manual 1-2 © National Instruments Corporation
MXI-2 cable
VXIplug&play diskette
MXI-2 Description
MXI-2 is the second generation of the National Instruments MXIbus
product line. The MXIbus is a general-purpose, 32-bit, multimaster
system bus on a cable. MXI-2 expands the number of signals on a
standard MXI cable by including all VXIbus interrupts, VXIbus
triggers, VXIbus CLK10, and all of the VMEbus utility bus signals
(SYSFAIL*, SYSRESET*, and ACFAIL*).
Because MXI-2 incorporates all of these new signals into a single
connector, the standard VXI-MXI-2 can extend the triggers, interrupts,
and utility signals not only to other mainframes, but also to any
computers and devices equipped with MXI-2.
In addition, MXI-2 surpasses the data throughput of previous-
generation MXIbus products by defining new high-performance
protocols. MXI-2 is a superset of MXI. All accesses initiated by
MXIbus devices will work with MXI-2 devices. However, MXI-2
defines synchronous MXI block data transfers that surpass previous
block data throughput benchmarks. The new synchronous MXI block
protocol increases MXI-2 throughput to a maximum of 33 MB/s
between two MXI-2 devices. All National Instruments MXI-2 boards
can initiate and respond to synchronous MXI block cycles.
Note: In the remainder of this manual, the term MXIbus refers to MXI-2.
VXI-MXI-2 Description
The VXI-MXI-2 is an extended-class register-based VXIbus device
with optional Slot 0 capability so that it can reside in any slot in a
C-size or D-size VXIbus chassis. The VXI-MXI-2/B can reside in any
B-size VXIbus slot.
Note: D-size VXI mainframes have connections for a P3 connector. The
VXI-MXI-2, however, does not have this connector and, if configured as a
Slot 0 controller, cannot provide the necessary control for VXI devices that
need P3 support.