User manual US ROBOTICS 005689-03

[. . . ] This manual covers installation and operating instructions for the following U. S. Robotics modems: · Sportster 56K* faxmodem for Macintosh computers Sportster, U. S. Robotics logo are registered trademarks and Connections, x2, and the x2 logo are trademarks of U. S. Macintosh is a registered trademark and Mac is a trademark of Apple Computer, Inc. [. . . ] Memory that is available for use when the modem is turned on but that clears all information when the power is turned off. The modem's RAM holds the current operational settings, a flow control buffer, and a command buffer. Remote Digital Loopback A test that checks the phone link and a remote modem's transmitter and receiver. Remote Echo A copy of the data received by the remote system, returned to the sending system, and displayed on the screen. Permanent memory, not user-programmable. 31 Serial Transmission The consecutive flow of data in a single channel. Compare to parallel transmissions where data flows simultaneously in multiple channels. Start/Stop Bits The signaling bits attached to a character before the character is transmitted during asynchronous transmission. Terminal A device whose keyboard and display are used for sending and receiving data over a communications link. Differs from a microcomputer or a mainframe in that it has little or no internal processing capabilities. Terminal Mode Software mode that allows direct communication with the modem. Also known as command mode. 32 Throughput The amount of actual user data transmitted per second without the overhead of protocol information such as Start and Stop bits or frame headers and trailers. V. 8 The portion of the V. 34 specification that covers the handshaking process. V. 17 Fax A ITU-T standard for making facsimile connections at 14, 400 bps, 12, 000 bps, 9, 600 bps, and 7, 200 bps. V. 21 A ITU-T standard for modems operating in asynchronous mode at 300 bps, full-duplex, on public switched telephone networks. V. 22 A ITU-T standard for modem communications at 1200 bps, compatible with the Bell 212A standard observed in the U. S. The standard includes an automatic link negotiation fallback to 1200 bps and compatibility with Bell 212A/V. 22 modems. V. 27 ter A ITU-T standard for facsimile operations that specifies modulation at 4800 bps, with fallback to 2400 bps. V. 29 A ITU-T standard for facsimile operations that specifies modulation at 9600 bps, with fallback to 7200 bps. V. 32 A ITU-T standard for modem communications at 9600 bps and 4800 bps. V. 32 bis A ITU-T standard that extends the V. 32 connection range: 4800, 7200, 9600, 12, 000, and 14, 400 bps. V. 32 bis modems fall back to the next lower speed when line quality is impaired, fall back further as necessary, and also fall forward (switch back up) when line conditions improve. V. 34 An ITU-T standard with recommendations that currently allow data rates as high as 33, 600 bps. 33 V. 42 A ITU-T standard for modem communications that defines a two-stage process of detection and negotiation for LAPM error control. V. 42 bis An extension of ITU-T V. 42 that defines a specific data compression scheme for use during V. 42 connections. Xmodem The first of a family of error control software protocols used to transfer files between modems. [. . . ] Le matériel doit également être installé en suivant une méthode acceptée de raccordement. Dans certains cas, le réseau interne de la campagnie associeé avec une ligne individuelle peut être étendue en utilisant un connecteur conforme aux reglementations (rallonge de corde téléphonique). L'abonné ne doit pas oublier qu'il est possible que la conformité aux conditions énoncées ci-dessus n'empêche pas la 66 dégradation du service dans certaines situations. Actuellement, les entreprises de télécommunication ne permettent pas que l'on raccorde leur matériel à des jacks d'abonné, sauf dans les cas précis prévus par les tarifs particuliers de ces entreprises. [. . . ]