"A"
"B"
"C",
"D",
"E",
"F",
"G",
"H",
"I",
"J",
"K",
"L",
"M",
"N",
"O",
"P",
"Q",
"R",
"S",
"T",
"U",
"V",
"W",
"X",
"Y",
"Z"
'Ha' to 'Hd', 'He', 'Hf' to 'Hor', 'Hor' to 'Hz',
HALF-Duplex. Data flow in either direction, but not in both directions at the same time. There are a number of interface buses that only allow Half-Duplex operation, while some bus networks just add a redundant path in the opposite direction to allow communication in either direction at the same time. Operation in both directions at the same time is called Full-Duplex. An Abbreviation for half duplex is HDX.
HALF-POWER POINT. A point on a waveform or radar beam that corresponds to half the power of the
maximum power point.
HALF-WAVE RECTIFIER. A rectifier using only one-half of each cycle to change ac to pulsating dc. Half-Wave Rectifier Circuit.
HALF-WAVE VOLTAGE DOUBLER. Two half-wave voltage rectifiers connected to double the input
voltage.
HAND-SHAKE. The interchange of signals between a 'talker' and a 'listener' to exchange data on a bus. During a Handshake a listener [slave] indicates ready for data, a talker [master] indicates data ready, the slave then indicates data received. Read more on the Handshaking Protocol.
| Hard Disk. [HD] A flat, circular, rigid plate with a magnetizable surface on one or both sides used to store data. Also called a Hard Disk Drive [HDD]. Note: A hard disk is distinguished from a diskette [floppy Disk] by virtue of the fact that it is rigid and not considered removable. Manufacturers of Hard Disk Drives. |  Hard Disk Drive |
HARD-TUBE MODULATOR. A high-vacuum electron tube modulator that uses a driver for pulse forming. See Vacuum Tube.
HARMONIC. A frequency that is a whole-number multiple of a smaller base frequency. Of a sinusoidal wave, an integral multiple of the frequency of the wave.
HARNESS. An assembly of wires or cables, or wires and cables arranged so it may be installed or removed as a unit in the same electronic or electrical equipment. One or more insulated wires or cables, with or without helical twist; with or without common covering, jacket, or braid; with or without breakouts; assembled with two or more electrical termination devices; and so arranged that as a unit it can be assembled and handled as one assembly. Also refer to Cable Harness Discussion for additional information.
HDLC. High-level Data Link Control is a group of protocols for transmitting [synchronous] data Packets between Point-to-Point nodes. Data is organized into a frame in HDLC. HDLC protocol resides with Layer 2 of the OSI model, the data link layer.
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Next set of "H" Terms and definitions
