Transmission technique that recognizes current flows, rather than voltage levels. [Traditionally used in teletypewriter networks, incorporating batteries as the transmission power source.
An industrial signaling standard between transducers (transmitter) and measuring device (reliever). The signal is scaled between 4 and 20 mA by the transmitter.
A two-wire communications link in which the current through the wires is maintained by a master device - such as an Enabler FDM or a pump. A current loop performs better than a simple link like RS-232: longer distance signal transmission, better noise immunity, and the ability to power the two-wire transmitter through the same two wires. Usually, the current is fixed at a certain level and is normally flowing. A device that transmits a bit breaks the connection (stopping the current flow). Two current loops are sometimes used together to create a four-wire, full-duplex link.
a communication interface that uses Current instead of voltage for signaling
A Current Loop (typically 4 to 20 milliamps) is a method used to transmit signals in noisy environments.
Transmission system used on certain devices and offering better performance than the RS232C. It provides a high degree of immunity to interference and is easy to implement, but has not been standardised.
A type of physical layer used for serial communications between devices. Unlike RS232 which uses voltage levels to represent binary data, a current loop uses current flow or 'open circuit' (no current flowing). A single current loop (2 wires) provides a half duplex link. A current loop was originally created for industrial applications because it allows transmission on longer cables, and has good noise immunity (resistance to electomagnetic interference). There is no industry standard for current loop hardware, and hardware manufacturers have implemented variations of this idea. For example, two current loops are sometimes used together to create a four-wire, full-duplex link.
A data transmission scheme that looks for current flow rather than voltage levels. This systems recognizes no current flow as a binary zero, and having current flow as a binary one. Favored for its low sensitivity to cable impedance, and independence of a common ground reference; hence current loops do not introduce ground loops. MIDI is an example of a current loop interconnect system.
Method of data transmission. A mark (binary «1») is represented by current on the line, and a space (binary «0») is represented by the absence of current.
A two wire transmit/receive interface.
A current loop describes two different electrical signalling schemes.
