A report on Non-return-to-zero

The binary signal is encoded using rectangular pulse-amplitude modulation with polar NRZ(L), or polar non-return-to-zero-level code
Unipolar NRZ(L), or unipolar non-return-to-zero level
Non-return-to-zero space
Encoder for NRZS, toggle on zero
An example of the NRZI encoding, transition on 1
The opposite convention, transition on 0
Encoder for NRZI, toggle on one

Binary code in which ones are represented by one significant condition, usually a positive voltage, while zeros are represented by some other significant condition, usually a negative voltage, with no other neutral or rest condition.

- Non-return-to-zero
The binary signal is encoded using rectangular pulse-amplitude modulation with polar NRZ(L), or polar non-return-to-zero-level code

8 related topics with Alpha

Overall

An arbitrary bit pattern in various binary line code formats

Line code

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Pattern of voltage, current, or photons used to represent digital data transmitted down a communication channel or written to a storage medium.

Pattern of voltage, current, or photons used to represent digital data transmitted down a communication channel or written to a storage medium.

An arbitrary bit pattern in various binary line code formats

Common line encodings are unipolar, polar, bipolar, and Manchester code.

An example of Manchester encoding showing both conventions for representation of data

Manchester code

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Line code in which the encoding of each data bit is either low then high, or high then low, for equal time.

Line code in which the encoding of each data bit is either low then high, or high then low, for equal time.

An example of Manchester encoding showing both conventions for representation of data

The price of these benefits is a doubling of the bandwidth requirement compared to simpler NRZ coding schemes.

The binary signal is encoded using rectangular pulse-amplitude modulation with polar return-to-zero code

Return-to-zero

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Return-to-zero (RZ or RTZ) describes a line code used in telecommunications signals in which the signal drops (returns) to zero between each pulse.

Return-to-zero (RZ or RTZ) describes a line code used in telecommunications signals in which the signal drops (returns) to zero between each pulse.

The binary signal is encoded using rectangular pulse-amplitude modulation with polar return-to-zero code

This means that a separate clock does not need to be sent alongside the signal, but suffers from using twice the bandwidth to achieve the same data-rate as compared to non-return-to-zero format.

Seagate ST11R, an 8-bit ISA RLL hard disk controller produced in 1990.

Run-length limited

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Line coding technique that is used to send arbitrary data over a communications channel with bandwidth limits.

Line coding technique that is used to send arbitrary data over a communications channel with bandwidth limits.

Seagate ST11R, an 8-bit ISA RLL hard disk controller produced in 1990.
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One of the simplest practical codes, modified non-return-to-zero-inverted (NRZI), simply encodes a 1 as a magnetic polarity transition, also known as a "flux reversal", and a zero as no transition.

Group coded recording

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In computer science, group coded recording or group code recording (GCR) refers to several distinct but related encoding methods for representing data on magnetic media.

In computer science, group coded recording or group code recording (GCR) refers to several distinct but related encoding methods for representing data on magnetic media.

GCR is a modified form of a NRZI code, but necessarily with a higher transition density.

High-Level Data Link Control

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Bit-oriented code-transparent synchronous network layer protocol developed by the International Organization for Standardization (ISO).

Bit-oriented code-transparent synchronous network layer protocol developed by the International Organization for Standardization (ISO).

On synchronous links, the data is NRZI encoded, so that a 0-bit is transmitted as a change in the signal on the line, and a 1-bit is sent as no change.

Bit rate

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Number of bits that are conveyed or processed per unit of time.

Number of bits that are conveyed or processed per unit of time.

In this case, the gross bit rate is equal to the symbol rate or pulse rate of 125 megabaud, due to the NRZI line code.

Bit stuffing in CAN after five equal bits.

Bit stuffing

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Insertion of non-information bits into data.

Insertion of non-information bits into data.

Bit stuffing in CAN after five equal bits.

The NRZI coding scheme transmits a 0 bit as a signal transition, and a 1 bit as no change.