ZyXEL Elite 2864 User Guide - Page 243

RS: Abbreviation of recommended standard. RTS/CTS: See CTS/RTS. RXD: Line for the received data on a serial port following RS-232C. Security function: Features of the ZyXEL modems which help deny illegitimate contacts to your computer system through telephone lines. Self-test: Ability of the modem to check its components and operations for faults. Serial port: Communication path through which data is transferred bitwise. Only one wire each is available for transmitted and received data. Shareware: A distribution method for software. The author lets the user try out the fully functional software for a certain amount of time at no charge. If the customer wants to keep and use the product after the period, he must pay the requested fees. This method depends heavily on the honesty of the user. Signal to noise ratio: A measure for the signal quality of a connection. SILENCE: Status detected in voice mode. If the modem returns a silence message, no voice energy was detected after a connection was established. Speech digitalization: Changing spoken sound into digital data which can be processed and saved by a computer. S-register: Abbreviation of status-register. The currently used parameters are stored in the status registers. S-registers are a part of the modem's internal memory. SREJ: Selective Reject - extension of the V.42 protocol which allows the more efficient handling of retransmission of erroneous data blocks. Start bit: In asynchronous transfers, a new character is introduced by the start bit. Symbol speed: Speed at which a signaling unit is transferred. In modern modem modulation, a signaling unit is no longer a single bit. Thus, the bit speed is different from the symbol speed. Stop bit: In asynchronous transfers, every character is terminated by one or two stop bits which show where a character ends. Synchronous : In synchronous transfer, a dedicated control signal line transmits a clock signal which paces the transmitted data. In highspeed connections, the transfer between two modems is always synchronous, even if the DCE to DTE connection is asynchronous. T.30: A standard for fax transfers. TAE6: A standard for a telephone wall outlet used in some countries, particularly in Germany. Glossary-7