National Instruments NI-VXI User Manual
Page 128
Glossary
© National Instruments Corporation
G-5
NI-VXI User Manual
D
Data Transfer Bus
One of four buses on the VMEbus backplane. The DTB is used by a
bus master to transfer binary data between itself and a slave device.
decimal
Numbering system based upon the 10 digits 0 to 9. Also known as
base 10.
de-referencing
Accessing the contents of the address location pointed to by a pointer.
default handler
Automatically installed at startup to handle associated interrupt
conditions; the software can then replace it with a specified handler.
DIR
Data In Ready. This is a bit in the Response register of a message-
based device that indicates that the device is ready to accept data from
its Commander.
DIRviol
Data In Ready violation. A type of word serial protocol error that
occurs when the Commander attempts to write data to the device when
the device is not ready.
DOR
Data Out Ready. This is a bit in the Response register of a
message-based device that indicates that the device is ready to output
data to its Commander.
DORviol
Data Out Ready violation. A type of word serial protocol error that
occurs when the Commander attempts to read data from the device
when the device is not ready.
DRAM
Dynamic RAM (Random Access Memory); storage that the computer
must refresh at frequent intervals.
DTB
See Data Transfer Bus.
E
ECL
Emitter-Coupled Logic
embedded controller
A computer plugged directly into the VXI backplane. An example is
the National Instruments VXIpc-850.
END
Signals the end of a data string.