A New Way to Connect: USB Device

by Joe Chow

In recent years, most computers connect to external devices in a new way, known as Universal Serial Bus (USB). USB is an easy way to connect to numerous types of devices including printers, digital cameras, game pads, joysticks, keyboards, mouse devices, and storage devices etc. As USB is a very commonly used standard, let us look at it in more detail and see how it is supported in the University.

USB versions

The latest version of USB is called the USB version 2.0; its speed is up to 480 Mbps. However, some old computers and old USB devices belong to version 1.0 and 1.1, and they support only 12 Mbps. However, all these versions are inter-compatible.

Support of USB in CityU

All the computers in CityU should support USB 1.1 or above. For Dell desktop PCs of more than 2 years (e.g. model like GX200, GX400 and Precision220), they support version 1.1 only and most of their USB ports are at the back of the PCs. For the latest models (e.g. GX260, GX270 and Precision360), the USB ports, which support version 2.0, are installed at the front of the PCs and are normally covered by a movable door near the bottom of the PCs. For public PCs like those in lecture theatres, classrooms and express terminals, USB hubs are installed. Please find out more by visiting them or calling us if you need help.

Connecting USB devices to your computer

You can connect a USB device to your computer while the computer is turned on.
However, DO NOT plug or unplug a USB device, especially a storage device, while the device is in use, or you may damage your files.

If necessary, connect the USB device to a power source, as some devices need extra power to drive. Standard USB port only provides 500mA which is not sufficient for most devices. If your USB device does not have an attached USB cable, then plug one into a corresponding USB port on the device and plug the other end of the cable into an USB port on your computer. A standard symbol for USB port looks like this:


If your computer doesn't have a free USB port, you may need to add a USB hub and connect other USB devices to the ports on the hub. In fact, you can cascade as many as 127 devices in this way. You don't need to install any software to use a USB hub. Some USB devices, such as some USB keyboards like those in Lecture Theatres and most classrooms, contain a hub so that you can plug additional USB devices into them.

Common problems in using USB

If a USB device doesn't work:

  1. If a message on the screen indicates that you don't have the necessary software to operate the device, you may not be able to connect to the Internet and automatically download the software necessary to use the device. You can also contact the manufacturer of the device to find out how to obtain and install the necessary software.
  2. Some devices do not need power but it cannot support long USB cable due to various reasons like power diminishing effect, so make sure the extension cable is not too long or else you need to install a USB hub with power in the middle. This is the reason why some USB devices are not functioning with the external USB ports under the keyboards in the lecture theatres and classrooms. This problem has been sorted out recently by installing new USB hubs in front of the PCs near the floppy drive.
  3. If the device has a power cord, make sure the cord is plugged into a working electrical outlet and the device is turned on.
  4. Some USB devices, such as printers, need to warm up for a few minutes after you turn them on. For more information, see the documentation that comes with the device.
  5. Make sure the USB cable connectors are plugged in properly and that the cables aren't damaged or frayed.
  6. After unplugging the device from the USB port, wait for a few seconds before you plug it back in again.

Key benefits of using USB

  1. USB is a very common standard and almost every computer running nowadays supports it.
  2. There are USB converters that can convert other standards to USB standard. So it is highly compatible.
  3. You can plug and unplug devices while your computer is turned on. The installation is very simple.
  4. You can attach up to 127 devices to each USB port on your computer.
  5. You can transfer information at a fast rate, up to 48 Mbps for each USB port (USB version 2.0) on your computer. That is near the speed of an ordinary IDE hard disk transfer rate.