Data circuit-terminating equipment

related topics
{system, computer, user}
{math, number, function}

A data circuit-terminating equipment (DCE) is a device that sits between the data terminal equipment (DTE) and a data transmission circuit. It is also called data communications equipment and data carrier equipment.

In a data station, the DCE performs functions such as signal conversion, coding, and line clocking and may be a part of the DTE or intermediate equipment. Interfacing equipment may be required to couple the data terminal equipment (DTE) into a transmission circuit or channel and from a transmission circuit or channel into the DTE.

Although the terms are most commonly used with RS-232, several data communications standards define different types of interfaces between a DCE and a DTE. The DCE is a device that communicates with a DTE device in these standards. Standards that use this nomenclature include:

A general rule is that DCE devices provide the clock signal (internal clocking) and the DTE device synchronizes on the provided clock (external clocking). D-sub connectors follow another rule for pin assignment. DTE devices usually transmit on pin connector number 2 and receive on pin connector number 3. DCE devices are just the opposite: pin connector number 2 receives and pin connector number 3 transmits the signals.

Usually, the DTE device is the terminal (or computer), and the DCE is a modem.

When two devices, that are both DTE or both DCE, must be connected together without a modem or a similar media translator between them, a kind of crossover cable must be used, i.e. a null modem for RS-232 or as usual for Ethernet.


External links

Full article ▸

related documents
VESA Local Bus
Standard-definition television
GE-200 series
Internetwork Packet Exchange
InterMezzo (file system)
VSE (operating system)
Linux framebuffer
IBM PC keyboard
Magnavox Odyssey²
Skinny Call Control Protocol
Red Book (audio CD standard)
ISO 7816
Motorola 88000
Links (web browser)
Local loop
Motorola 68030
Darlington transistor
Distributed-queue dual-bus
Terminal adapter
Unijunction transistor
32-bit application