Industrial Cameras, Industrial Imaging and Machine Vision - Wholesale Distributor - Aegis Electronic Group
USB vs GigE Camera For Machine Vision Applications
SHOULD IT BE A USB OR A GigE CAMERA?
Choosing to use a USB versus a GigE camera for a machine vision application is simple. There is one question that will clarify the choice. How far is it from the camera to the processor?
Surprisingly, the choice between a USB versus a GigE camera has very little to do with the camera itself. There are really no feature sets, functions, or capabilities between one camera or the other. Pick the camera based on features, then check for the output you decide on. That stated an examination of the two deciding factors for the USB vs GigE output port is next. The two factors are length and speed.
LENGTH IS CRITICAL
The USB vs GigE choice is less about the connector and more about the length of the cable. If the distance from the camera to the processor is more than 16 feet (~5 meters), then cable selection becomes critical. USB is rated for 5 meters or less, while GigE cable can function to about 100 meters. USB extenders can extend the signal quality and speed up to about 25 meters. But beyond 25 meters, signal degradation and data speeds are not reliable with USB cables. So the GigE option becomes a requirement beyond that 25-meter point.
BANDWIDTH IS NEXT
A USB 3.0 cable allows for about 625 pictures per second from a 12-megapixel camera. That stems from its data speed of 5 gigabytes per second. This allows five times the volume per second more than the GigE cable. There are four wires within the cables.
The GigE cable allows about 125 pictures per second from a 12-megapixel camera. That stems from its data speed of 1 gigabyte per second. It was designed for reliable signal quality over long distances. Most people would recognize a GigE cable as being the blue or yellow one that connects computers to a LAN or wired internet. GigE stands for “ gigabyte ethernet”, as in “1 gigabyte of data speed over an ethernet style cable”. There are eight wires within the cable.
USING A USB CAMERA BETWEEN 5 TO 25 METERS
A high data application may be rendered inept from lower data speeds over a long GigE cable. Thankfully there have been a number of solutions brought to market that solve the need for USB speeds between 5 and 25 meters.
USB Extenders grant access to data-intensive applications up to around 82 feet (25 meters). Beyond that, a USB extension system actually incorporates ethernet cables, which result in lower transmission speeds.
WILL CONNECTORS FORCE A CHOICE OF USB vs GigE CAMERA?
Connecting the desired camera to the desired processor is the last piece of the puzzle. Thankfully there is an endless combination of plugs that can be put on either end of a cable. Websites offer an easy method to customize the originating connector and end connector to a USB cable.
Machine vision applications are not limited by the camera being a USB or a GigE. It is the distance from the camera to the processor then data speed that are the deciding factors for which camera output will be chosen.
