National Instruments NI-VXI User Manual
Page 129
Glossary
NI-VXI User Manual
G-6
© National Instruments Corporation
EOS
End Of String; a character sent to designate the last byte of a data
message.
ERR
Protocol error
Event signal
A 16-bit value written to a message-based device’s Signal register in
which the most significant bit (bit 15) is a 1, designating an Event (as
opposed to a Response signal). The VXI specification reserves half of
the Event values for definition by the VXI Consortium. The other half
are user defined.
Extended Class device
A class of VXIbus device defined for future expansion of the VXIbus
specification. These devices have a subclass register within their
configuration space that defines the type of extended device.
extended controller
The external controller plus all of the extending controllers to which it
is directly connected. An example is an AT-MXI connected to a
VXI-MXI.
Extended Longword
A form of Word Serial communication in which Commanders and
Serial Protocol
Servants communicate with 48-bit data transfers.
extending controller
A mainframe extender that has additional VXIbus controller
capabilities. An example is the VXI-MXI.
external controller
A desktop computer or workstation connected to the VXI system via a
MXI interface board. An example is a standard personal computer with
a PCI-MXI-2 installed.
F
FHS
Fast Handshake; a mode of the Word Serial Protocol which uses the
VXIbus signals DTACK* and BERR* for synchronization instead of
the Response register bits.
FIFO
First In-First Out; a method of data storage in which the first element
stored is the first one retrieved.
G
GPIB
General-Purpose Interface Bus; the industry-standard IEEE 488 bus.