USRobotics 33600, x2/56K user manual Parity, Protocol, Remote Echo

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The modem uses MNP 2-4 and MNP 5 error correction and data compression techniques that are incorporated in recommendation ITU-T V.42.

NVRAM

Non Volatile Random Access Memory which can be programmed by the user with data that are stored when the modem is powered down. The modem includes this kind of memory to store a default configuration defined by the user and loaded into random access memory (RAM) upon power up.

Parity

Error detection method that checks the correctness of transmitted characters. Verification of characters has been replaced by more reliable and efficient block

control methods, including Xmodem types of protocols and the ARQ protocol implemented in the modem. Two communicating computers must use the same kind of parity.

Protocol

Set of rules and procedures describing communications between different devices. Protocols vary, but communications equipment must use the same protocol in order to exchange data. Data formats, the ready to receive or transmit states, error detection and correction are some of the operations that can be defined in protocols.

Remote Echo

A copy of the data received by the remote system is sent back to the transmitting system and displayed on the screen. Remote echo is a function of the remote system and is often used in full duplex transmissions.

RTS/CTS

Hardware check used to tell an intelligent device to stop or resume data transmission.

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Contents User’s Manual 1997 Table of Contents Glossary Limited Warranty Appendix B Technical SpecificationsVoice Functions Appendix a Technical ReferenceHow a Modem Works IntroductionQuickly How Does Your Sportster Winmodem 33600 & x2/56K∗ Work ?Accurately Other FeaturesEfficiently With WindowsPackage Contents Installation Sportster Winmodem 33600 & x2/56K InstallationPlug and Play Insert the Modem Into the Computer Installation ProcedurePlug in the power plug and turn the computer on Run the Modem’s Installation Program If you choose Then try This COM port This IRQ Running the Installation Program on a Windows 95 System Installing the Communications Software Page Changing Country Setup under Windows Page Installation Test Using the ModemFactory Settings Resetting the Modem to Factory Settings Remember the Following Points When Using the Modem Remarks on Using the ModemUn-Installing the Modem Page Troubleshooting Problems and SolutionsSymptom Solution Modem does not Send AT commandsRespond when, Terminal mode, youUsing a certain Tone when you try toErrors There is no audibleModem Connection problemConnects itself Correctly toA fax, errors alter Transmission errorsIntercontinental Connections areBefore the Modems Connect If your PC reacts as Signals but fail toThough you are Online, but no callLink. If your screen displays random or garbage characters During Data TransfersDuring Fax Transmissions If You Are Still Having Problems Page Overview of Voice Functions Voice FunctionsSpeakerphone Application SettingsImplementing Voice Functions Voice ApplicationsInput/Output Source Selection Page Appendix a Technical Reference Main AT commandsBasic Command Set E0 Echo OFF E1 Modem displays keyboard commands Fn Sets online local echo of transmitted data ON/OFF Ln Controls speaker volume internals onlyHn Controls ON/OFF hook Displays the following informationVn Displays verbal/numeric result codes Xn Sets result code displayed. Default isXn Setting Result CodesFunctions Advanced Command Set Sets Error Control ARQ 1200 bps and higher Enables/disables data compressionSets Guard Tone Sets Transmit DataTD flow controlSets pulse rotary dial make/break ratio Writes current configuration to Nvram templatesSets Receive Data RD hardware flow control Controls Data Set Ready DSR operationsRegisters Reg Default FunctionSets the number of seconds the modem Page Bit Value Result Reg Default Function Reg Default Function Page Bit 4 Bit Result BitValue 128 Reserved Page Page Sportster Winmodem X2/56K Specifications Electrical power Safety CE MarkElectromagnetic Compatibility Page Glossary Analog signalsAsynchronous transmission Baud rateBits BitBps BufferDigital signals Data modeError correction DuplexFallback Fax modeFlow control Local EchoParity ProtocolRemote Echo Serial transmission Terminal modeSynchronous transmission TerminalXON/XOFF Page Limited Warranty Advised of the Possibility of Such Damages Page 024.1388-00