Glossary
© National Instruments Corporation G-5 NI SPEEDY-33 User Manual
DIO Digital Input/Output
DMA Direct Memory Access—A meth od by which data is transferred to/from
computer memory from/to a device or memory on the bus while the
processor does something else. DMA is the fastest method of transferring
data to/from computer memory.
DR Data Receive
drivers/driver software Software that controls a specific hardware device such as a DAQ device.
DSP (1) Digital Signal Processing
(2) Digital Signal Processor—a specialized microprocessor designed
specifically for digital signal processing, generally in real-time. Digital
signal processors can also be used to perform general-purpose
computation, though they are not optimized for this function.
dual-access memory Memory that can be sequentially accessed by more than one controller or
processor but not simultaneously accessed. Also known as shared memory.
E
EEPROM Electrically Erasable Programmable Read-Only Memory—ROM that can
be erased with an electrical signal and reprogrammed.
EMC electromagnetic compliance
EMI electromagnetic interference
event The condition or state of an analog or digital signal.
expansion connector A connector on the device for connecting additional signals to the DSP.
F
F (1) Fahrenheit—A temperature measurement scale.
(2) farad—A measurement unit of capacitance.
FIFO First-In First-Out memory buffer—The first data stored is the first data sent
to the acceptor. FIFOs are often used on DAQ devices to temporarily store
incoming or outgoing data until that data can be retrieved or output.