| What is a frame grabber? What types are there? | | | | analog) and computers. Many frame grabbers also |
| How do you know when you will need one? | | | | have features that will benefit almost any |
| These are some of the questions we will answer | | | | industrial vision system. Trigger inputs and outputs |
| in this artical. First off what is a frame grabber? A | | | | are just one of these beneficial features. An |
| frame grabber is a conduit for video being | | | | output can be programmed to trigger a light for |
| transferred from a camera to a computer. So | | | | precisely the right exposure timing and another |
| look at it this way, if a camera needs one to plug | | | | output can be used to control the cameras |
| into a computer then it is called a interface | | | | shutter timing. |
| camera because it needs the frame grabber to | | | | Frame grabbers can also posses processing |
| interface with the computer. Chances are if you | | | | engines that range from Look-Up tables, Field |
| have one of these cameras it will be using s-video | | | | Programmable Gate Arrays, general purpose |
| or BNC composite cables . If the camera can plug | | | | processors and Digital Signal Processors. |
| directly into the computer without needing a | | | | Frame grabbers also vary in the design in which |
| interface it is called a direct connect camera. If | | | | they plug into the computer or the way their bus |
| you are using a camera that plugs into the | | | | architecture is designed. The Peripheral |
| computer directly chances are it is a USB or | | | | Component Interconnect frame grabbers (PCI) |
| Firewire camera. So a frame grabber is essentially | | | | and its newer higher bandwidth PCI-X and PCI |
| a link between cameras and computers. But not | | | | Express are the main bus architectures. Frame |
| all interface cameras need frame grabbers and | | | | grabbers are also built in AGP (Accelerated |
| not all direct connect cameras can be used | | | | Graphics Processing), ISA, PC104Plus, CompactPCI |
| without them. There are different types of frame | | | | and VME 9VERSAmodule Eurocard) So, as you |
| grabbers, analog frame grabbers and digital frame | | | | can see, there is a multitude of frame grabbers |
| grabbers. Analog frame grabbers digitize an analog | | | | that will use USB and Firewire inputs and some |
| video signal sent by the camera. They then send | | | | with S-video and BNC inputs. There are basic |
| the digital data to the host computers memory. | | | | frame grabbers that serve as interface boards |
| Therefore taking a camera that was only built to | | | | and advanced frame grabbers that trigger certain |
| be plugged in to a monitor or a recording device | | | | functions. |
| and making the data digital for real time edit and | | | | They have several types of bus architectures, |
| control from the host computer. | | | | but that still doesn't answer the question of what |
| Digital frame grabbers take data that has already | | | | system really needs a frame grabber? If you |
| been digitized in the camera and manage its | | | | have an interface or analog camera that you |
| transfer rate over the computer bus to the host | | | | want plugged into a computer then you will have |
| memory. So all digital frame grabbers do is | | | | to have a frame grabber but if you have a digital |
| manages the data as its being transferred to the | | | | camera or direct connect camera you will not |
| host computers memory for storage and real | | | | have to have one. Many imaging systems still use |
| time edit and control. Frame grabbers do not just | | | | one because or other features the boards can |
| act as an interface between cameras (digital or | | | | come with. |