ZyXEL Elite 2864 User Guide - Page 239

Data packet: Block of data which is framed by error control groups. A block consists of up to 256 8-bit groups. Data packets are used in synchronous transfer. Data pump: The important module doing modulation and demodulation for a modem. The data pump is decisive for the quality and the speed of a modem's transfer capabilities. DCD: Data Carrier Detected - a control signal line of the RS-232C interface. DCE: Data Circuit Terminating Equipment or Communications Equipment - a modem is a DCE. Demodulation: Transferring analog signals into digital data bits. Digital: Digital data consists of a series of bits. A bit may have only one of two states. Analog data may have any value. Digital loopback test: A modem test procedure which transfers the received digital data back to the modulator and transmits them out. DIP switch: Also called a mouse's piano. Perfectly suited to break finger nails and pencils. DIP switches are abundant in the world of electronic equipment. They are used to set certain parameters on a printer, modem or other peripheral devices. You will not find any DIP switches in ZyXEL modems. ZyXEL modems let you perform all settings from the front panel or through command sequences. DLE: Name of an ASCII code (see table in appendix E). This control code is used in voice mode to separate data segments and control segments. DSP: Digital signal processor. ZyXEL modems are equipped with this/these device(s). DSPs generate, process and analyze all signals. DSR: Data Set Ready - a control signal line of the RS-232C standard. DTE: Data Terminal Equipment - a computer or a terminal. DTR: Data Terminal Ready - a control signal line of the RS-232C standard interface. Some computers set this signal when they are turned on, even if they are not able to receive data. Echo: For a modem user, echo has two meanings: A modem can return all received characters to its local terminal/computer so they can be seen on-screen. The other meaning of the term "echo" is that part of the analog signal the modem sent out is bounced back by the telephone network to the modem's receiver, mixing there with the remote modem's signal. EDR: Extended Distinctive Ring - A feature of ZyXEL modems which helps to distinguish between data, fax and voice calls. Glossary-3