USRobotics 33600, x2/56K user manual Data mode, Digital signals, Duplex, Error correction

Data mode

Mode in which the fax/modem can send and receive data files. A standard modem without facsimile capabilities is always in data mode.

DCE

(Data Carrier Equipment) Termination equipment of the data circuit. In this manual, this term applies to modems that establish and control the data link on the telephone network.

Digital signals

Discreet and uniform signals. In this manual, the term refers to bits 0 and 1.

DTE

(Data Terminal Equipment) Data processing terminal equipment. Generally, a computer or terminal generates data or is the final destination of data.

Duplex

Defines a communications channel capable of transmitting signals in both directions (half duplex or full duplex).

Full duplex: Simultaneous flow of signals in two directions. In micro-computer communications, full duplex can refer to suppressing the local echo of transmitted characters..

Half Duplex: Signal flow in two directions, but only in one at a given time. In micro-computer communications, half duplex can refer to enabling of the local echo that causes the modem or the software to send a copy of transmitted data to the screen of the transmitting computer.

Error correction

Various techniques that check the reliability of the characters or data blocks. The V.42 and MNP2-2, 10 error correction protocols use error detection (using a CRC type control code) and re-transmit erroneous frames (ARQ).

Sportster Winmodem 33600 & x2/56K - User's manual 63