1. current loop

2. Computer terminal Historical
Typically terminals communicate with the computer via a serial port, often using an RS-232 or a current loop serial interface

3. Railgun - Mathematical formula
as the length of the current loop increases

4. Cathode - Etymology
He fundamentally defined his arbitrary orientation for the cell as being that in which the internal current would run parallel to and in the same direction as a hypothetical magnetizing current loop around the local line of latitude which would induce a magnetic dipole field oriented like the Earth's

5. Modem - History
Modems grew out of the need to connect teleprinters over ordinary phone lines instead of the more expensive leased lines which had previously been used for current loop–based teleprinters and automated telegraphs. In 1942, IBM adapted this technology to their unit record equipment and were able to transmit punched cards at 25 bits/second.

6. Anode - Etymology
He fundamentally defined his arbitrary orientation for the cell as being that in which the internal current would run parallel to and in the same direction as a hypothetical magnetizing current loop around the local line of latitude which would induce a magnetic dipole field oriented like the Earth's

7. Coilgun
Coilguns are distinct from railguns, as the direction of acceleration in a railgun is at right angles to the central axis of the current loop formed by the conducting rails

8. RS Connectors
Presence of a 25-pin D-sub connector does not necessarily indicate an RS-232-C compliant interface. For example, on the original IBM PC, a male D-sub was an RS-232-C DTE port (with a non-standard current loop interface on reserved pins), but the female D-sub connector on the same PC model was used for the parallel Centronics printer port. Some personal computers put non-standard voltages or signals on some pins of their serial ports.

9. RS-232 - Related standards
A 20 mA current loop uses the absence of 20 mA current for high, and the presence of current in the loop for low; this signaling method is often used for long-distance and optically isolated links

10. Control flow - Early exit from loops
When using a count-controlled loop to search through a table, it might be desirable to stop searching as soon as the required item is found. Some programming languages provide a statement such as break (most languages), exit, or last (Perl), whose effect is to terminate the current loop immediately and transfer control to the statement immediately following that loop.

11. Electrical reactance - Inductive reactance
An inductor consists of a coiled conductor. Faraday's law of electromagnetic induction gives the counter-emf (voltage opposing current) due to a rate-of-change of magnetic flux density through a current loop.

12. Alarm management - Alarm problem history
The sensors relayed their information to the control instruments via 4-20 mA current loop in the form of twisted pair wiring

13. Telex - Development
The first option, sometimes called local or Current loop|loop service, provided a 60 milliampere loop circuit from the exchange to the customer teleprinter

14. Amazon tax - California
Ross, The San Francisco Chronicle, January 19, 2011 This legislation will close the current loophole in tax law which has allowed out-of-state companies to avoid collecting California sales and use tax, stated Skinner

15. Attention - Neural correlates of attention
* Through top-down sensitivity control, higher cognitive processes can regulate signal intensity in information channels that compete for access to working memory, and thus give them an advantage in the process of competitive selection. Through top-down sensitivity control, the momentary content of working memory can influence the selection of new information, and thus mediate voluntary control of attention in a recurrent loop (endogenous attention).

16. Magnetic field - History
From the outside, the field of a dipole of magnetic charge has the exact same form as that of a current loop when both are sufficiently small. Therefore, the two models differ only for magnetism inside magnetic material.

17. Magnetic field - Amperian loop model and the B-field
After Oersted discovered that electric currents produce a magnetic field and Ampere discovered that electric currents attracted and repelled each other similar to magnets, it was natural to hypothesize that all magnetic fields are due to electric current loops. In this model developed by Ampere, the elementary magnetic dipole that makes up all magnets is a sufficiently small Amperian loop of current I. The dipole moment of this loop is where is the area of the loop.

18. Magnetic field - Magnetic torque on permanent magnets
The Amperian loop model also predicts the same magnetic torque. Here, it is the field interacting with the Amperian current loop through a Lorentz force described below. Again, the results are the same although the models are completely different.

19. Magnetic moment - Current loop definition
Practitioners using the current loop model generally represent the magnetic field by the solenoidal field 'B', analogous to the electrostatic field 'D'.

20. Magnetic moment - Magnetic moment of a solenoid
A generalization of the above current loop is a coil, or solenoid. Its moment is the vector sum of the moments of individual turns. If the solenoid has N identical turns (single-layer winding) and vector area 'S',

21. Magnetic moment - Units
For example, in the Magnetic moment#Current loop definition|current loop definition, the area is measured in square meters and I is measured in Ampere (unit)|amperes, so the magnetic moment is measured in ampere–square meters (A m2)

22. Magnetic moment - Force on a moment
force, proportional to the magnetic field gradient, acting on the magnetic moment itself. There has been some discussion on how to calculate the force acting on a magnetic dipole. There are two expressions for the force acting on a magnetic dipole, depending on whether the Magnet#Two models for magnets: magnetic poles and atomic currents|model used for the dipole is a current loop or two monopoles (analogous to the electric dipole).

23. Magnetic moment - Force on a moment
The force obtained in the case of a current loop model is

24. Magnetic moment - Magnetic dipoles
A magnetic dipole is the limit of either a current loop or a pair of poles as the dimensions of the source are reduced to zero while keeping the moment constant. As long as these limits only applies to fields far from the sources, they are equivalent. However, the two models give different predictions for the internal field (see below).

25. Dipole
For the current loop, the magnetic dipole moment points through the loop (according to the right hand grip rule), with a magnitude equal to the current in the loop times the area of the loop.

26. Dipole
However, to the best of our knowledge, the electron's magnetic moment is not due to a current loop, but is instead an intrinsic property of the electron

27. Dipole
The only known mechanisms for the creation of magnetic dipoles are by current loops or quantum-mechanical spin (physics)|spin since the existence of magnetic monopoles has never been experimentally demonstrated.

28. Electricity meter - Communication methods
Often, meters designed for semi-automated reading have a serial port on that communicates by infrared LED through the faceplate of the meter. In some multi-unit buildings, a similar protocol is used, but in a wired bus using a serial port|serial current loop to connect all the meters to a single plug. The plug is often near a more easily accessible point.

29. Building Automation - Types of inputs and outputs
Analog inputs are used to read a variable measurement. Examples are temperature, humidity and pressure sensor which could be thermistor, Current loop#Process-control use|4-20 mA, 0-10 volt or platinum resistance thermometer (resistance temperature detector), or wireless sensors.

30. Programmable Logic Controller - Discrete and analog signals
Current loop|Current inputs are less sensitive to electrical noise (i.e. from welders or electric motor starts) than voltage inputs.

31. MEMS magnetometer - Voltage sensing
The location of the current loop enables a more uniform Lorentz force distribution compared with the aforementioned U-shape cantilever beam

32. Universal asynchronous receiver/transmitter - Transmitting and receiving serial data
Historically, current (in current loops) was used in telegraph circuits

33. EIA-232 - Related standards
A 20mA digital current loop interface | current loop uses the absence of 20mA current for high, and the presence of current in the loop for low; this signaling method is often used for long-distance and optical isolator|optically isolated links

34. Thermoelectric - Seebeck effect
This was because the metals responded differently to the temperature difference, creating a current loop and a magnetic field

35. IEC 62056
* IEC :2002, Direct local data exchange (3d edition of IEC 61107) describes how to use COSEM over a local port (optical or current loop)

36. IEC IEC
The physical media are usually either modulated light, sent with an LED and received with a photodiode, or a pair of wires, usually modulated by a 20mA current loop

37. Highway Addressable Remote Transducer Protocol - Modes
In point-to-point mode, the digital part of the HART protocol can be seen as a kind of digital current loop interface.

38. Curie temperature - Weiss domains and surface and bulk Curie temperatures
The angular momentum of an electron is either +ħ/2 or - ħ/2 due to it having a spin of ½, which gives a specific size of magnetic moment to the electron; the Bohr Magneton. Electrons orbiting around the nucleus in a current loop create a magnetic field which depends on the Bohr Magneton and magnetic quantum number. Therefore the magnetic moments are related between angular and orbital momentum and affect each other. Angular momentum contributes twice as much to magnetic moments than orbital.

39. State Grid Corp - History
It also has an alternating current loop line in the Yangtze river delta, and three longitudinal alternating current lines that bring power to Southern China from the Northern region.

40. REXX - Repetitive loops
A program can break out of the current loop with the leave instruction, which is the normal way to exit a do forever loop, or can short-circuit it with the iterate instruction.

41. Teleprinter - Teleprinter operation
More than two teleprinters could be connected to the same wire circuit by means of a current loop.

42. Teleprinter - Teletypesetter
In later years the incoming 6-bit current loop signal was coupled directly into a minicomputer or mainframe for storage, editing, and eventual feed to a phototypesetting machine.

43. HP Functionality
For example, more memory (providing larger scrollback capability) could be easily added, the serial interface could be changed from RS-232 to current loop, etc

44. PDP-11 - LSI-11
The CPU microcode includes a debugger: firmware with a direct serial interface (RS-232 or current loop) to a Computer terminal|terminal

45. Dumb terminal - Popular VDUs
* RS232 serial ports (25-pin, ready to connect to a modem, yet some manufacturer-specific pin usage extended the standard, e.g. for use with 20-mA Digital current loop interface|current loops)

46. Dumb terminal - Dumb and Intelligent Terminals
Typically terminals communicate with the computer via a serial port via a null modem cable, often using an EIA RS-232 or RS-422 or RS-423 or a Digital current loop interface|current loop serial interface

47. Teletype Model 33 - Interface
As the price of electronic terminals dropped in the late 1970s, the current loop was gradually replaced by an RS-232 interface.

48. PDP-8 - Input/Output
Over time I/O systems such as DECtape|magnetic tape, RS-232 and current loop dumb computer terminal|terminals, punched card readers, and magnetic disk|fixed-head disks were added

49. Java keywords - List
:Used to resume program execution at the end of the current loop body. If followed by a label, continue resumes execution at the end of the enclosing labeled loop body.

50. Stayin' Alive - Beginnings
After listening to the drum track of the already-recorded Night Fever, the group and producer Albhy Galuten selected two bars from that track, re-recorded them as a recurrent loop on a separate tape, and proceeded with sessions for Stayin' Alive

51. Dumb terminals - Early VDUs
* RS-232 serial ports (25-pin, ready to connect to a modem, yet some manufacturer-specific pin usage extended the standard, e.g. for use with 20-mA Digital current loop interface|current loops)

52. SAE J Signaling
The pilot line circuitry examples in SAE J1772:2001 show that the current loop CP-PE is connected permanently via a 2740Ω resistor making for a voltage drop to from +12V to +9V when a cable is hooked up to the charging station which activates the wave generator

53. RSTS/E - Communication
The connection might be a local computer terminal with a 20 Ampere|mA current loop interface, an RS-232 interface (either local serial port or remote connection via modem), or by an ethernet connection utilizing DECnet or LAT

54. ⛽ - Communications components
The technology for communicating with gas pumps from a point of sale or other controller varies widely, involving a variety of hardware (RS-485, RS-422, current loop, and others) and proprietary software protocols. Traditionally these variations gave pump manufacturers a natural tie-in for their own point-of-sale systems, since only they understood the protocols.[ IFSF Management Intro, sec 1.1 Background history]

55. Snubber - Electrical systems
Inductive elements are often unintentional, but arise from the current loops implied by physical circuitry

56. Intelligent buildings - Types of inputs and outputs
Analog inputs are used to read a variable measurement. Examples are temperature, humidity and pressure sensors which could be thermistor, Current loop#Process-control use|4-20 mA, 0-10 volt or platinum resistance thermometer (resistance temperature detector), or wireless sensors.

57. Remote Terminal Unit - Analog inputs
An RTU can monitor analog inputs of different types including 0-1mA, Current loop#Analog|4–20mA current loop, 0–10V., ±2.5V, ±5.0V etc.

58. Access Control Systems - Access control system topologies
'1. Serial controllers.' Controllers are connected to a host PC via a serial EIA-485|RS-485 communication line (or via 20mA current loop in some older systems). External RS-232/485 converters or internal RS-485 cards have to be installed, as standard PCs do not have RS-485 communication ports.

59. Synchronous Data Link Control
or Current loop|loop facilities, on switched or dedicated, Two-wire circuit|two-wire or Four-wire circuit|four-wire circuits, and with full-duplex and half-duplex operation..

60. Switching amplifier - Electromagnetic interference
* Avoid inductive coupling from various current loops in the power stage into the wiring.

61. Signal conditioning - Applications
Types of devices that use signal conditioning include signal filters, instrument amplifiers, sample-and-hold amplifiers, isolation amplifiers, signal isolators, multiplexers, bridge conditioners, analog-to-digital converters, digital-to-analog converters, frequency converters or translators, voltage converters or inverter (electrical)|inverters, frequency-to-voltage converters, voltage-to-frequency converters, current-to-voltage converters, current loop converters, and charge converters.

62. 4-20 mA
In electrical signalling (telecommunication)|signalling an analog 'current loop' is used where a device must be monitored or controlled remotely over a pair of conductors. Only one current level can be present at any time.

63. 4-20 mA
Given its analog nature, current loops are easier to understand and debug than more complicated digital fieldbuses, requiring only a handheld digital multimeter in most situations. Using fieldbuses and solving related problems usually requires much more education and understanding than required by simple current loop systems.

64. 4-20 mA
Additional digital communication to the device can be added to current loop using HART Protocol. Digital process buses such as FOUNDATION Fieldbus and Profibus may replace analog current loops.

65. 4-20 mA - Process-control use
Since input terminals of instruments may have one side of the current loop input tied to the chassis ground (earth), analog isolators may be required when connecting several instruments in series.

66. 4-20 mA - Process-control use
(A 4-wire instrument has a power supply input separate from the current loop.) Another loop may contain two passive chart recorders, a passive pressure transmitter, and a 24 V battery

67. 4-20 mA - Long circuits
Analog current loops were occasionally carried between buildings by dry pairs in telephone cables leased from the local telephone company. 4–20mA loops were more common in the days of analog telephony. These circuits require end-to-end direct current (DC) continuity. DC continuity is not available over a microwave radio, optical fibre, or a multiplexed telephone circuit connection.

68. 4-20 mA - Discrete control
These devices can be employed for any remote control need a designer might imagine. For example, a current loop could actuate an evacuation Siren (noisemaker)|siren or command synchronized traffic signals.

69. 4-20 mA - Two-way radio use
The office would have a remote control unit that would operate the taxi company base station over a current loop circuit

70. Fieldbus - Description
This would be the equivalent of the currently used Current loop|4-20 mA communication scheme which requires that each device has its own communication point at the controller level, while the fieldbus is the equivalent of the current local area network|LAN-type connections, which require only one communication point at the controller level and allow multiple (hundreds) of analog signal|analog and Digital data|digital points to be connected at the same time

71. Pseudovector - Physical examples
Consider an electrical current loop in the plane that inside the loop generates a magnetic field oriented in the z direction

72. List of computing and IT abbreviations - A
* Active current loop|ACL—Active Current Loop

73. Hydrogen line - Cause
This logic fails here because the electron is not spatially displaced from the proton, but encompasses it, and the magnetic dipole moments are best thought of as tiny current loops

74. Development system
A lower cost SDK-85 System Design Kit board was provided with an 8085 CPU, 8355 ROM containing a debugging monitor program, 8155 RAM and 22 I/O, 8279 hex keypad and 8-digit 7-segment LED, TTY (Teletype) 20mA current loop serial interface. Pads were available for one more 2Kx EPROM and another 256byte RAM 8155 I/O Timer/Counter could be optionally added. All data, control and address signals were available on dual pin headers and a large prototype area was provided.

75. Magnetic field strength - History
From the outside, the field of a dipole of magnetic charge has the exact same form as that of a current loop when both are sufficiently small

76. 1960s two-way radio remote control consoles used direct current loops
Tone remote - History
1960s two-way radio remote control consoles used direct current loops

77. UART - Break condition
The spacing condition of a current loop line is indicated by no current flowing, and a very long period of no current flowing is often caused by a break or other fault in the line

78. Digital current loop interface
For Digital signal|digital serial communications, a 'current loop' is a communication interface that uses electrical current|current instead of voltage for signaling. Current loops can be used over moderately long distances (tens of kilometres), and can be interfaced with opto-isolator|optically isolated links.

79. Digital current loop interface - History
A digital current loop uses the absence of current for high (space or break), and the presence of current in the loop for low (mark)

80. Digital current loop interface - Electrical characteristics
The maximum electrical resistance|resistance for a current loop is limited by the available voltage. Current loop interfaces usually use voltages much higher than those found on an RS-232 interface, and cannot be interconnected with voltage-type inputs without some form of level translator circuit.

81. Digital current loop interface - Examples
* MIDI (Musical Instrument Digital Interface) is a digital current loop interface.

82. Digital current loop interface - Examples
* The HART Protocol is a digital current loop interface designed to be compatible with analog current loop wiring.

83. Single-board microcontroller - Communications and user interfaces
Early systems might implement a serial port to provide RS-232 or current loop

84. Stellar magnetic field - Field generation
Because the major currents flow in the direction of conductive mass motion (equatorial currents), the major component of the generated magnetic field is the dipole field of the equatorial current loop, thus producing magnetic poles near the geographic poles of a rotating body.

85. Exhibition Place - Public transit
The first loop began operations in 1916 and was located at the current loop location. In 1923 the loop was relocated to the southeast near the Princes' Gate. With the construction of the National Trade Centre it was re-located back to the original location in 1996.

86. Atlanta Marathon - Route
From 1997 to 2009, about 90% was run along the same course used for the 1996 Summer Olympics, ending near Turner Field (built as Centennial Olympic Stadium in the A-FC stadium parking lot). The current loop course, takes in many major sites within Atlanta, including the Olympic rings.

87. Teletype Model 28 - Interface
There were different kinds of Model 28 interfaces that included Rotary Dial, current loop and polar signaling.

88. For More Information, Visit:
The Art of Service