3Com 1.024.1644-00 manual Glossary Online fallback/fall forward, Originate mode, Parity, Protocol

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Glossary

online fallback/fall forward

A feature that allows a high-speed, error-control modem to monitor line quality and fall back to the next lower speed in a defined range if line quality diminishes. As line conditions improve, the modem switches up to the next higher speed.

originate mode

The mode used by your modem when initiating an outgoing call to a destination modem. The transmit/receive frequencies are the reverse of the called modem, which is in answer mode.

parity

A simple error-detection method that checks the validity of a transmitted character. Character checking has been surpassed by more reliable and efficient forms of error checking, including V.42 and MNP 2-4 protocols. Either the same type of parity must be used by two communicating computers, or both may omit parity.

protocol

A system of rules and procedures governing communications between two or more devices. Protocols vary, but communicating devices must follow the same protocol in order to exchange data. The format of the data, readiness to receive or send, error detection and error correction are some of the operations that may be defined in protocols.

RAM

Random Access Memory is memory that is available for use when the modem is turned on, but that clears of 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. Remote echoing is a function of the remote system.

48 56K Voice Faxmodem Internal - User’s Guide

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Contents 56K Voice Faxmodem Internal Page Table of Contents Page Table of Contents Page Welcome to 56K*Information Access Product Features Back Channel Link Rates Upload Speeds Flash ROM Upgradable Determining Available Resources Control PanelDetermining Your Version of Windows Click PropertiesWindows 95 version Plug and Play Installation How to Prepare for Plug and Play InstallationHow to Insert the Modem into the Computer Serial NumberPage Page Page Page Installing Modem Drivers With Windows Versions 950 and 950a Moving Through the New Hardware Found ScreensPage COM Port Click More Info… Installing Modem Drivers With Windows Version 950b Using the Update Device Driver Wizard ScreensPage COM Port Click More Info… Word about COM Ports and IRQs How to Change the Modem’s Settings Page How to Insert the Modem into the Computer Page Page Page Page Restart Now Software Installation WindowsType of Modem Initialisation StringFlow Control Possible Solution Read This FirstTroubleshooting Possible Solution Possible Solution Possible Solution Troubleshooting Possible Solution Support Resources Are You Still Having Problems? Support ResourcesAnalogue loopback Analogue signalsAnswer mode ApplicationGlossary Binary digit bit Glossary Auto dialBaud rate Bit rateCharacters per second CPS Data modeGlossary Character Class 1 Digital signals Default Detect phase GlossaryFacsimile Glossary Error controlFax mode Flow controlNonvolatile memory Nvram Local echoModem OFF/ON hookParity Originate modeGlossary Online fallback/fall forward ProtocolStart/stop bits Terminal modeSerial transmission Terminal32 bis 22 bis27ter See online fall back/fall forwardYmodem 42 bisXmodem Ymodem GTechnical Reference Dials the specified phone number, includes the following Technical ReferenceITU-T answer sequence En Sets local echoDisplays the following information Ln Controls speaker volume internals onlyTechnical Reference Hn Controls ON/OFF hook Mn Operates speakerNumeric codes Verbal codesTechnical Reference Sets result code displayed, default is 11/RINGINGTechnical Reference An Enables/disables additional result code subsets see Xn Resets modemDisplays a list of ampersand & commands Cn Controls Carrier Detect CD signalSets Guard Tone Fn Loads a read-only non-programmable factory configurationKn Enables/disables data compression Hn Sets Transmit Data TD flow control see also &Rn300 bps Sets pulse rotary dial make/break ratio No restrictions on the minimum speed for Wn Writes current configuration to Nvram templates Yn Sets break handling64 56K Voice Faxmodem Internal User’s Guide Register Default Function RegistersDefault Function Bit Value ResultTechnical Reference Register Default Function S13Timer S27 See the instructions for S13 S34 Bit Fax Commands +FCLASS=n Sets the mode of operation+FTH=n +FRH=nDisplayed As a number Words Description Regulatory CE ComplianceLimited Warranty