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and joints, and travel back down the cable toward the source, causing interference as primary reflections. Secondary reflections can also occur at the cable starts, allowing interference to persist as repeated echoes of old data. These reflections also act as bottlenecks, preventing the signal power
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to carry electromagnetic signals with minimal reflections and power losses. The distinguishing feature of most transmission line cables is that they have uniform cross-sectional dimensions along their length, giving them a uniform electrical
374:. Antenna cables are sometimes used for internet connections; however, RG-6 should not be used for 10BASE2 (which should use RG-58) as the impedance mismatch can cause phasing problems with the baseband signal.
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bus. At the two ends of the bus, resistors connect between the positive (high) and negative (low) signal wires either in internally terminated bus couplers or external connectorized terminators.
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The MIL-STD-1553B bus must be terminated at both ends to minimize the effects of signal reflections that can cause waveform distortion and disruption or intermittent communications failures.
131:, and power losses. Less commonly, a terminator is also placed at the driving end of the wire or cable, if not already part of the signal-generating equipment.
358:. If the bus network is not properly terminated, too much power will be reflected, causing all of the computers on the bus to lose network connectivity.
285:
conditions. The signal is locked between two actively regulated voltage levels, which results in superior performance over a standard active terminator.
404:
systems used terminator cards with 178 Ω pullup resistors on the multi-drop address and data lines and 383 Ω on the single-drop signal lines.
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Optionally, a high-impedance terminator (1000 to 3000 ohms) may be used in vehicle applications to simulate a future load from an unspecified device.
265:
151:. Signal terminators are designed to specifically match the characteristic impedances at both cable ends. For many systems, the terminator is a
163:
at the frequencies relevant to the system. Examples include 75-ohm resistors often used to terminate 75-ohm video transmission coaxial cables.
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518:"FPT is a terminator that self-terminates. One that matches itself to the line perfectly, thereby removing all reflections at the endpoints
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155:, with a value chosen to match the characteristic impedance of the transmission line and chosen to have acceptably low parasitic
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Signal termination often requires the installation of a terminator at the beginning and end of a wire or cable to prevent an
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off the end of the transmission line. Reflections at the ends of unterminated transmission lines cause
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loads may require other passive components such as inductors, capacitors, or transformers.
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Radio frequency currents tend to reflect from discontinuities in the cable, such as
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that keeps the voltage used for the terminating resistor(s) at a constant level.
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321:, commonly known as CAN Bus, uses terminators consisting of a 120 ohm resistor.
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units use terminators. SCSI is primarily used for storage and backup. An
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Connectorized terminators are available with or without safety chains.
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104:, or power loss. The terminator is usually placed at the end of a
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Types of transmission line cables include balanced line such as
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networks absolutely must have proper termination with a 50 ohm
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levels and misoperation of digital systems. Reflections in
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is a type of single-ended SCSI terminator with a built-in
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is often in the form of a cap, threaded to screw onto an
475:"Clock Termination Techniques and Layout Considerations"
415:
resistor values of 78.7 ohms 2 watt 1% are used on the
335:
Dummy loads are commonly used in HF to EHF circuits.
310:to compensate for variations in terminator power.
100:from being reflected back from each end, causing
273:Forced perfect termination (FPT) can be used on
64:of the line. Termination prevents signals from
8:
222:Types of electrical and signal terminators
88:in radio transmitter transmission lines.
366:A terminating resistor for a television
466:
127:of the cable and hence minimize signal
528:Digital Equipment Corporation (1979).
234:terminators often consist of a single
389:terminator-and-bootstrap card from a
7:
27:Transmission line impedance matching
347:10BASE2 cable end signal terminator
25:
142:Transmission line cables require
206:); and unbalanced lines such as
289:Signal Termination Applications
139:from reaching the destination.
60:with a device that matches the
80:systems cause such effects as
72:, which can produce ambiguous
1:
398:Digital Equipment Corporation
56:is the practice of ending a
455:Telecommunications pedestal
588:
500:Forced Perfect Termination
328:
269:Forced perfect termination
261:Forced perfect termination
29:
18:Forced perfect termination
253:terminators consist of a
238:; however, significantly
149:characteristic impedance
62:characteristic impedance
339:Ethernet coaxial 50 ohm
319:Controller area network
314:Controller Area Network
530:"Unibus Specification"
393:
362:Antenna network 75 ohm
348:
270:
119:), and is designed to
54:electrical termination
45:
385:
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40:
440:Electrical connector
30:For other uses, see
567:Electronic circuits
283:over and undershoot
445:Electrical network
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349:
271:
144:impedance matching
92:Transmission lines
46:
308:voltage regulator
304:active terminator
255:voltage regulator
106:transmission line
58:transmission line
16:(Redirected from
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535:. Archived from
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216:10BASE5 Ethernet
210:(Radio antenna,
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356:BNC terminator
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329:Main article:
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188:Landline Phone
176:Cat-6 Ethernet
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82:video ghosting
74:digital signal
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542:on 2016-03-04
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368:coaxial cable
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298:All parallel
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208:coaxial cable
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180:Parallel SCSI
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172:twisted pairs
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78:analog signal
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544:. Retrieved
537:the original
523:
512:, retrieved
510:, 1990-08-03
499:
493:
482:. Retrieved
469:
450:MIL-STD-1553
429:
427:
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417:MIL-STD-1553
412:
411:
408:MIL-STD-1553
395:
365:
350:
334:
317:
303:
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277:buses where
275:single ended
272:
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230:
165:
141:
133:
125:AC impedance
115:(such as in
102:interference
95:
53:
47:
413:Terminating
372:F connector
168:ladder line
161:capacitance
129:reflections
110:daisy chain
50:electronics
32:Termination
561:Categories
546:2014-06-06
514:2016-12-19
484:2021-01-03
461:References
331:Dummy load
325:Dummy load
157:inductance
136:connectors
86:power loss
70:distortion
66:reflecting
44:terminator
391:PDP-11/34
192:XLR audio
98:RF signal
434:See also
240:reactive
236:resistor
200:Firewire
153:resistor
352:10BASE2
281:remove
232:Passive
227:Passive
402:Unibus
387:Unibus
378:Unibus
279:diodes
251:Active
246:Active
204:Serial
170:, and
540:(PDF)
533:(PDF)
504:(PDF)
480:. CTS
478:(PDF)
121:match
84:, or
572:SCSI
396:The
300:SCSI
294:SCSI
212:CATV
184:ADSL
159:and
123:the
117:SCSI
42:SCSI
508:IBM
218:).
196:USB
113:bus
108:or
48:In
563::
506:,
214:,
202:,
198:,
194:,
190:,
186:,
182:,
178:,
52:,
549:.
487:.
174:(
34:.
20:)
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