Duplex Architectures
Duplex
refers to the means of bandwidth usage in a serial system. The
two common means of bi-directional serial communication are full duplex
and half duplex. Half-duplex communication involves a transmitter and a
receiver connected to each end of the same wire or pair of wires.
Because the same transmission line both sends and receives data,
devices cannot send data in both directions at the same time. First, one
device transmits over the wire(s) to the receiver of the second device.
When the first device finishes transmitting, both devices switch the
connections from their transmitter to their receiver, or vice versa. The
device that was receiving data can then transmit over the line.
In full-duplex communication, the devices use a separate wire (or pair of
wires) for simultaneous transmission in each direction. Thus, the devices
do not switch between transmitting and receiving.
In a differential serial bus (such as RS-422 or RS-485), a half-duplex
system transmits and receives over the same twisted pair of wires. Thus,
half-duplex communication is often referred to as
two-wire
communication. Likewise, full-duplex communication is often referred to
as
four-wire
communication, because the full-duplex system uses a
separate pair of wires for communication in each direction.
Содержание ENET-232 Series
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Страница 5: ...Using Help Conventions Navigating Help Searching Help Printing Help File Topics ...
Страница 17: ...How to Use this Help File To use this help file refer to the following flow chart and the appropriate topics ...
Страница 21: ...Serial Hardware Overview PCI Kits PXI Kits USB Kits ENET Kits ExpressCard Kits PCMCIA Kits ...
Страница 24: ...PCI 485I RS 485 two port isolated RS 485 four port isolated ...
Страница 27: ...PXI 8423 RS 485 two port isolated RS 485 four port isolated ...
Страница 63: ...Save Pending Changes To save your changes to this item click Save ...
Страница 65: ...Restore Defaults To reset the fields to their default values at any time click the Defaults button ...
Страница 98: ...0 LPVOID l_SerialInterface sizeof l_SerialInterface LPDWORD l_ByteCount NULL ...
Страница 127: ...2 PORT LEDs USB Serial Hardware LEDs ...
Страница 139: ...Connecting the Cables to a Four Port PXI Serial Board ...
Страница 141: ...67 58 50 41 33 24 16 7 TXD 9 RI 9 ...
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Страница 181: ...How many serial ports can I have on my machine You can have up to 256 serial ports ...
Страница 189: ...nslookup hostname If you still cannot communicate with your device contact National Instruments ...
Страница 201: ...Glossary Prefixes Symbols A B C D E F G H I K L M P R S T U V ...
Страница 203: ...Symbols degrees ohms percent ...
Страница 204: ...A A amperes ANSI American National Standards Institute ...
Страница 205: ...B b bits B bytes baud bits per second bps bits per second ...
Страница 206: ...C C Celsius COM Computer Output Microform used in reference to a communication port CTS clear to send ...
Страница 208: ...E EIA Electronic Industries Association EMI electromagnetic interference ENET Ethernet ...
Страница 209: ...F FCC Federal Communications Commission FIFO First In First Out ft feet ...
Страница 210: ...G G ground ...
Страница 211: ...H HSI handshake input HSO handshake output Hz Hertz ...
Страница 213: ...K Kbaud kilobits per second ...
Страница 214: ...L LED light emitting diode ...
Страница 215: ...M m meters MB megabyte ...
Страница 216: ...P PC personal computer PCI Peripheral Components Interconnect ...
Страница 218: ...S s seconds SCSI Small Computer Systems Interface ...
Страница 220: ...U UART Universal Asynchronous Receiver Transmitter ...
Страница 221: ...V V volts VDC volts direct current VXI VME eXtensions for Instrumentation ...
Страница 222: ...Important Information Warranty Copyright Trademarks Patents Warning Regarding Use of NI Products Compliance ...