USB - Universal Serial Bus
The term USB is widely known and used. It is used for a very wide range of devices and is very simple to use. But have you really put much thought into how it works?
The Universal Serial Bus
USB is essentially a standard for data transmission.
USB stands for Universal Serial Bus. Its name gives away a lot about the interface:
Universal - It is a widely accepted standard capable of interacting with most devices
Serial - It uses serial data transmission
Bus - It is a communication system used for transmitting data
The USB is now the most commonly used input/output port with modern computers. This universal implementation makes for the very convenient and easy interchangeability of peripheral devices.
USB stands for Universal Serial Bus. Its name gives away a lot about the interface:
Universal - It is a widely accepted standard capable of interacting with most devices
Serial - It uses serial data transmission
Bus - It is a communication system used for transmitting data
The USB is now the most commonly used input/output port with modern computers. This universal implementation makes for the very convenient and easy interchangeability of peripheral devices.
The USB Cable
What is inside a USB cable?
A standard USB cable actually consists of four smaller cables as detailed in the diagram below:
A standard USB cable actually consists of four smaller cables as detailed in the diagram below:
* This is the most common colour coding system used although others may exist.
The red and black cables are used for power purposes and the green / white cables are used for data transmission.
Great power!
The fact that the red and black wires can provide power to devices is of huge benefit to the system. This essentially means that any device connected to a computer via USB can be provided with up to 5v of power to operate. Without this functionality, any USB device that you connected to the computer would need an external power source e.g. batteries or another cable.
Imagine how the operation of your mouse, keyboard, memory stick would be affected if an extra power source was required... not great!
The red and black cables are used for power purposes and the green / white cables are used for data transmission.
Great power!
The fact that the red and black wires can provide power to devices is of huge benefit to the system. This essentially means that any device connected to a computer via USB can be provided with up to 5v of power to operate. Without this functionality, any USB device that you connected to the computer would need an external power source e.g. batteries or another cable.
Imagine how the operation of your mouse, keyboard, memory stick would be affected if an extra power source was required... not great!
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Plug and Play
One of the joys of using USB devices is the "Plug and Play" nature. This essentially means that the devices can simply be plugged in and they are ready to use with little to no setup. Key features of this plug and play feel are:
Automatic detection - When a USB device is plugged in it is automatically detected by the computer.
Automatic recognition and setup- When a USB device is plugged in, the computer will automatically determine what type of device it is and it will load the correct driver software. The driver software is what enables the computer to correctly communicate with the device.
Example - Is a user connects a new USB mouse to a computer, the computer will determine that it is indeed a mouse and it will load the available mouse software. This will enable the user to then use the new mouse with minimal to no setup.
Setup Assistance - If an unusual or new type of device is plugged in and the correct device driver is not already available on the computer system, the USB protocol will inform the user that new device software is needed. Some systems will attempt to search for the correct software and suggest it to the user whereas other systems will require the users to manually search for it.
Automatic detection - When a USB device is plugged in it is automatically detected by the computer.
Automatic recognition and setup- When a USB device is plugged in, the computer will automatically determine what type of device it is and it will load the correct driver software. The driver software is what enables the computer to correctly communicate with the device.
Example - Is a user connects a new USB mouse to a computer, the computer will determine that it is indeed a mouse and it will load the available mouse software. This will enable the user to then use the new mouse with minimal to no setup.
Setup Assistance - If an unusual or new type of device is plugged in and the correct device driver is not already available on the computer system, the USB protocol will inform the user that new device software is needed. Some systems will attempt to search for the correct software and suggest it to the user whereas other systems will require the users to manually search for it.
Convenience
Devices that make use of USB are incredibly convenient to use. Some of the pros and cons of USB are detailed in the table below:
Benefits |
Drawbacks |
It is a universally accepted standard which makes for convenient usage and a large amount of available support. |
Cable length is limited to only 5 meters |
Devices are automatically detected by a computer once connected |
Extra devices such as hubs are required to extend cables if necessary |
Drivers are automatically searched for and loaded. If not present then user is prompted to install them. |
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External power source is not needed as the USB cable can supply 5V |
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If errors in transmission are detected, the USB protocol will inform the user to re transmit the data |
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USB still supports older devices i.e. it is backwards compatible |
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