The advantage of GigE Vision over analog standards is that it is digital, does not require an image acquisition card, and is more focused on image processing functions; the advantage of GigE Vision over Camera Link is that it has a long transmission distance, does not require an image acquisition card, and is more focused on image processing functions; compared to IEEE 1394, GigE Vision has a higher maximum data rate and a longer transmission distance; compared to USB 2.0, the advantage of GigE Vision is that it is a more complete standard, has a higher maximum data rate, and a longer transmission distance.
One main problem plaguing GigE Vision is that the Ethernet protocol is based on packet switching. Every time a data packet is received, an interrupt is initiated to the CPU. The transmission of large amounts of image data exhausts the CPU from dealing with the interruption of data packets, resulting in packet loss, delay, etc. The following different improvement measures can be taken to address this problem: select jumbo frame settings, increase the interrupt throttling rate, increase the value of the receive descriptor, and unload protocol operations and image reassembly.
For 2K*2K 8-bit 15fps image data, when jumbo frame technology is used, there are 42,000 interruptions per second, and the CPU occupancy rate is 21%; when the interrupt throttling rate is increased, there are 7,000 interruptions per second and the CPU occupancy rate is 9%; when jumbo frame, interrupt throttling rate, and receive descriptor value are used at the same time, there are 1,100 interruptions per second and the CPU occupancy rate is 7.4%. At the same time, to reduce the transmission delay of control information on Ethernet, a GPIO card is installed on the PC so that the PC can directly send a defective ejection control signal to the ejection mechanism after recognizing the image.
The CPU usage rate of USB 2 million pixel data transmission is about 3%, while the CPU usage rate of Giga Camera 2 million pixels adopts jumbo frame, does not adopt interrupt flow technology, and improves receiving descriptor technology under the same conditions, the CPU usage rate is about 11%. If the jumbo frame is not adopted and the standard frame is adopted, the CPU usage rate is about 18%.
GigE Vision's MIL driver is the key to GigE Vision's hardware independence. You only need to select the appropriate network card and write the corresponding XML format MIL driver to apply GigE Vision. The MIL driver sends real images to be processed, with low CPU usage; supports point-to-point network or switch network configuration; supports single-port or multi-port NIC; can control up to 16 cameras at the same time; supports camera features of mandatory standards and recommended standards; and can even customize camera features
Kommentare