Glossary
Glossary–4
VX4380 256-Crosspoint Relay Matrix Module User Manual
may be installed in a VXIbus mainframe. An instrument module may
contain more than one device. Also, one device may require more than one
instrument module.
Interface Device
A VXIbus device that provides one or more interfaces to external equipment.
Interrupt Handler
A functional module that detects interrupt requests generated by Interrupters
and responds to those requests by requesting status and identity information.
Interrupter
A device capable of asserting VMEbus interrupts and performing the
interrupt acknowledge sequence.
IRQ
The Interrupt ReQuest signal, which is the VMEbus interrupt line that is
asserted by an Interrupter to signify to the controller that a device on the bus
requires service by the controller.
Local Bus
A daisy-chained bus that connects adjacent VXIbus slots.
Local Controller
The instrument module that performs system control and external interface
functions for the instrument modules in a VXIbus mainframe or several
mainframes. See Resource Manager.
Local Processor
The processor on an instrument module.
Logical Address
The smallest functional unit recognized by a VXIbus system. It is often used
to identify a particular module.
Mainframe
Card Cage. For example, the Tektronix VX1410 Intelliframe, an operable
housing that includes 13 C-size VXIbus instrument module slots.
Memory Device
A storage element (such as bubble memory, RAM, and ROM) that has
configuration registers and memory attributes (such as type and access time).
Message
A series of data bytes that are treated as a single communication, with a well
defined terminator and message body.
Message Based Device
A VXIbus device that supports VXI configuration and communication
registers. Such devices support the word serial protocol, and possibly other
message-based protocols.