Overview
VTI Instruments EX2500 is the industry's first gigabit LAN-based VXI slot 0 interface, merging Ethernet's robust architecture and widespread infrastructure and the fast emerging LXI standard for instrumentation with the popular VXIbus platform. Recognizing that many system designers require hardware that is compatible with legacy systems, but also desire to adopt new technologies, the EX2500 integrates key features of the LXI standard to create a versatile interface that extends the VXIbus to an external host through the power of Ethernet.
The Power of LXI
The VXI TTL trigger bus is a powerful component of VXI-based
systems and is used to facilitate hardware handshaking between
modules, freeing up the CPU for other tasks. With the introduction
of the EX2500A, all eight of the VXI TTL triggers can now be
extended across multiple mainframes and to other LXI devices
through the LXI Trigger Bus compliant front panel connectors
(LVDS). Additionally, the EX2500A incorporates the LXI standard
VXI-11 instrument discovery mechanism, greatly simplifying
integration within hybrid systems.
Data Transfer Rates
As technology moves toward more data intensive applications in
the functional test and data acquisition environments, the ability to
quickly offload data to the host controller for processing is critical.
The EX2500A is a high-speed gigabit serial communications device
and has been optimized for transferring blocks of data in excess
of 40 MB/s, faster than any other serial interface currently found
in the industry today. A high-performance DMA controller is used
during block moves to achieve superior transfer rates. This is
accomplished without compromising traditional message-based
(word-serial) command performance.
Simplified Cabling and Connectivity
Communication back to the host processor is achieved using a
standard CAT5e Ethernet cable. Distances between mainframe and
host of up to 200 meters can be realized. A fiberoptic connection
is available if even greater distances are required. Wireless control
of VXI instruments is also now possible through the use of wireless
routers. The EX2500A achieves top performance when connected
to a gigabit LAN interface which is also a standard item in CPU
motherboards. Low-cost gigabit Ethernet switches can be used to
connect multiple mainframes to a single host. For legacy systems,
SMB connectors are provided for single-line trigger input/output as
well as external reference clock input/output.
Familiar Software Interfaces
The EX2500A is fully compliant with the VXIplug&play
specifications and implements VISA as the API communication
layer. A standard VISA I/O library is included and integrates
seamlessly with either Agilent Technologies or National
InstrumentsTM versions of VISA. This greatly simplifies
installation of the EX2500A into legacy systems using the VISA
protocol and preserves any investment in existing TPS and
driver development by eliminating the need for costly code
modifications.
The VXI Resource Manager is executed automatically at power
up time and all system resources are allocated without the
need to run a separate utility. The EX2500A runs an embedded
web interface and system status including installed VXI
hardware, memory allocation, IP configuration and logical
address information can be viewed through an .html LXI-style
web page. Direct communication to installed devices through
message or register-based commands, can be achieved
through this interface. Firmware updates to the module can
be accomplished through a few mouse clicks.
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