18-Aug-2018, 17:28
Basics USB!
The Universal Serial Bus is based on a serial architecture. This means that the data is transferred bit by bit, in series, from one device to another. This enables high-speed data transfer with a low error rate. In addition, you save yourself an additional power cable, since the interface also serves to transfer energy. Data is also sent and received in both directions (I / O interface).
A bus connection had in its beginnings a master-slave structure. There is a master (or host), such as a notebook or computer, that controls data transfer. Its USB port has a slave (peripheral device) connected to it which hosts the data and controls it. These include printers, cameras or keyboards. If the data is on the PC, you can send it to another device if necessary. Since 2001, the master-slave structure has eased. The data transfer is also possible between two peripheral devices. For example, a camera can send images via USB cable directly to a printer or the data from a smartphone can be stored on a stick. This technology is called USB On The Go (OTG) and is indicated in the USB symbol by a green arrow with the words "On-The-Go". As a rule, the functionality is limited in this type of data transfer.
Low speed / high speed
In addition to the two lines for the power supply (+ 5V and GND), there are two data lines. The data transmission takes place symmetrically over two twisted lines. The one line transmits the data signal, the other the inverted data signal. One speaks of a differential transference. The voltage difference in the signal voltage is twice as large as if the data signal were transmitted to ground. At the receiver, the difference between the two signals is formed, with signal interference are hidden. This increases transmission safety, suppresses common-mode noise and improves electromagnetic compatibility.
To route slow devices such as the keyboard, mouse, and even fast devices such as modems or video cameras over the same bus, the transmission has been divided into channels.
There is a low-speed channel up to 1.5 Mbit / s (mouse, keyboard) and a medium-speed channel with 12 Mbit / s (ISDN, audio) which are routed via the same interface. A high-speed channel with 480 MBit / s (video, storage media) is also provided (USB 2.0).
In addition to the speed category, there are also different priorities in the transmission. The highest priority is given to devices that provide data in real time and where data flow must not be interrupted. The middle priority is for interrupt transmissions when z. B. a device wants to get the attention of the processor. The lowest priority is mass transfer devices. The transmission of this data is usually not particularly urgent.
The Universal Serial Bus is based on a serial architecture. This means that the data is transferred bit by bit, in series, from one device to another. This enables high-speed data transfer with a low error rate. In addition, you save yourself an additional power cable, since the interface also serves to transfer energy. Data is also sent and received in both directions (I / O interface).
A bus connection had in its beginnings a master-slave structure. There is a master (or host), such as a notebook or computer, that controls data transfer. Its USB port has a slave (peripheral device) connected to it which hosts the data and controls it. These include printers, cameras or keyboards. If the data is on the PC, you can send it to another device if necessary. Since 2001, the master-slave structure has eased. The data transfer is also possible between two peripheral devices. For example, a camera can send images via USB cable directly to a printer or the data from a smartphone can be stored on a stick. This technology is called USB On The Go (OTG) and is indicated in the USB symbol by a green arrow with the words "On-The-Go". As a rule, the functionality is limited in this type of data transfer.
Low speed / high speed
In addition to the two lines for the power supply (+ 5V and GND), there are two data lines. The data transmission takes place symmetrically over two twisted lines. The one line transmits the data signal, the other the inverted data signal. One speaks of a differential transference. The voltage difference in the signal voltage is twice as large as if the data signal were transmitted to ground. At the receiver, the difference between the two signals is formed, with signal interference are hidden. This increases transmission safety, suppresses common-mode noise and improves electromagnetic compatibility.
To route slow devices such as the keyboard, mouse, and even fast devices such as modems or video cameras over the same bus, the transmission has been divided into channels.
There is a low-speed channel up to 1.5 Mbit / s (mouse, keyboard) and a medium-speed channel with 12 Mbit / s (ISDN, audio) which are routed via the same interface. A high-speed channel with 480 MBit / s (video, storage media) is also provided (USB 2.0).
In addition to the speed category, there are also different priorities in the transmission. The highest priority is given to devices that provide data in real time and where data flow must not be interrupted. The middle priority is for interrupt transmissions when z. B. a device wants to get the attention of the processor. The lowest priority is mass transfer devices. The transmission of this data is usually not particularly urgent.
Aavik U-280 / Audio Physic Cardeas / Melco N1ZS + D100 / Melco Switch S100 / KECES P8 Dual / Transparent Audio PowerWave X / Cable: Audioquest, Shunyata, Transparent, Ansuz Digitalz A2 Ethernet, USB
Remote: iPad-Pro
Roon Nucleus+(B), Lifetime / Qobuz Studio Sublime
Remote: iPad-Pro
Roon Nucleus+(B), Lifetime / Qobuz Studio Sublime
Germany / Bavaria
