What is the maximum transmission distance of the Machion Vision USB3.0 cable?
Answer: In January 2013, the USB3 Vision standard formulated by AIA (Automated Imaging Association) was officially launched, marking the establishment of the USB3.0 interface standard in the machine vision industry. However, the maximum transmission distance of the USB3.0 cable assembly is not defined in the standard. But in actual use, we can evaluate from the two perspectives of power supply voltage drop and signal attenuation, and determine the maximum transmission distance based on actual use experience. USB3.0 power supply voltage drop requirements ( from the USB3.0 standard) the conductor of the power cord is 18AWG, its maximum resistance is 2.48Ω/100m, and the maximum cable length is 7.7m.
USB3.0 signal attenuation requirements ( from the USB3.0 standard)
The fundamental frequency of the USB3.0 signal is 2.5GHz. Based on the fundamental frequency and the signal wire conductor 26AWG, the maximum transmission distance is only 7.5÷1.9=3.95m. This is the cable transmission length measured by the 5Gpbs rate benchmark, but the actual Machion Vision USB3.0 rate is usually only 3.2Gbps.
Based on the theoretical estimation and the practical application experience of machine vision, the maximum distance of the USB3.0 cable can reach 8m.
What are the different types of the common BNC connectors?
Answer: The BNC connector is a radio frequency connector with a frequency range of 0~4GHz. It is used for low power and has a bayonet connection mechanism. It can be connected and separated quickly, has the characteristics of reliable connection, good vibration resistance, and convenient connection and separation. It is suitable for frequent connection and separation occasions, and is widely used in radio equipment and test instruments.
At present, the most common standard size BNC connector on the market includes two specifications of 50 ohm and 75 ohm. In addition, in the field of video transmission, there are two small size versions of BNC: Mini-BNC and Micro-BNC. Among them, Micro-BNC is the HD-BNC used for CXP cables in machine vision, that is, high-density BNC. The size of HD-BNC is 51% smaller than traditional BNC connectors and 40% smaller than DIN1.0/2.3, which can achieve 4 times the interconnection performance of BNC.
How to calculate the required transmission bandwidth of the MV cable between the industrial camera and the data acquisition card?
Answer: Because it is an industrial camera, its video data will not be compressed in any format when it is transmitted to the capture card. The calculation formula is as follows: Video data rate = camera resolution x color depth x frame rate ÷ 8
Example: A GigE interface industrial camera with a resolution of 500w, a frame rate of 10 fps, and a color depth of 24 bits. The video data rate is: 5,000,000x10x24÷8=144MB/s, and the gigabit network cable rate is 1000bps÷8= 125MB/s, so the camera should use 10 Gigabit network cable. Knowledge Expansion
1) Resolution: The number of pixels of each image collected by the camera generally corresponds to the number of pixels arranged on the target surface of the photoelectric sensor, such as 1920*1080.
2) Pixel depth: the number of bits per pixel data, usually 8bit, 10bit, 12bit, 24bit. The resolution and pixel depth together determine the size of the image. For example, for 5 million pixels with a pixel depth of 8bit, the entire image should have 5 million*8/8/1024/1024=4.8M (1024Byte=1KB, 1024KB=1M). Increasing the pixel depth can enhance the accuracy of the measurement, but it also reduces the speed of the system and increases the difficulty of system integration (increased cables, change the outer diameter, etc.).
3) Maximum frame rate/line frequency: The speed at which the camera collects and transmits images. For area scan cameras, it is generally the number of frames per second (Frames/Sec, fps), and for line scan cameras, it is the number of lines per second (Hz). ).
How to improve cable crosstalk?
"Crosstalk" refers to unwanted signals generated by coupling between different pairs of wires in a cable. To put it simply, crosstalk means that electromagnetic interference between pairs will cause the signal on a pair of twisted pairs to affect the signal on the other pair. Crosstalk exists between the wire pairs in the same cable bundle, and a twisted pair will be interfered by multiple wire pairs. Cable crosstalk has a great impact on signal transmission, which may lead to communication loss and interruption of communication in severe cases. Therefore, "crosstalk" is an important indicator for judging the quality of communication cables.
Crosstalk is divided into "far-end crosstalk" and "near-end crosstalk".
Far End Crosstalk
Far-end rosstalk (FEXT) is a transmitter working at the far end of other twisted pairs in the same cable bundle, causing interference to the receiver at the other end of the twisted pair in the same direction. This kind of far-end crosstalk is smoothly attenuated through the loop transmission, so its impact is small, especially for long-distance cables. As shown in the picture.
Near End Crosstalk
Near-end crosstalk (NEXT) occurs at the same end. Transmitters working in other twisted pairs in the same cable bundle cause interference to receivers located at the same end in the opposite direction of the twisted pair. This near-end crosstalk is not smoothly attenuated through the loop transmission, so its impact is much greater than that of the far-end crosstalk.
As shown in the picture.
Port A --- Port Transmitting, Port B --- Port Receiving, the signal strength received by Port C is Near-End Crosstalk, and the signal strength received by Port D is Far-End Crosstalk.
What is PROFINET？
PROFINET is a communication standard for automation launched by Siemens and the PROFINET&PROFIBUS organization. Its essence is based on the IEEE Ethernet protocol, with flexible linear, ring, and star topologies. It has the characteristics of good real-time performance, high safety and reliability, high compatibility and low implementation cost, and is widely used in industrial automation.
PROFINET cable is an Ethernet cable developed according to the PROFINET protocol and generally adopts a star-quad structure. According to the application environment, it is divided into TYPE A (Fixed Installation), TYPE B (Occasionally Moving), TYPE C (Towing Chain Application), TYPE R (Robot Application).
How to Improve Cable CrosstalkHow to improve cable crosstalk?
As the transmission and transmission frequency of data cable communication continue to expand, the requirements for data transmission are getting higher and higher. The crosstalk of the sound quality is the quality index that affects the data communication cable. So how to improve the cable string?
1. Choose a reasonable pitch for twisting. The smaller the real-time twisted pitch, the smaller the crosstalk problem of the cable. However, the smaller the pitch, the worse the lay length of the production cable, and the longer the transmission, so the efficiency should be considered in the notification index, and the most reasonable pitch design should be selected.
2. Broadcast line pair distance reception. The farther the distance between a pair of wires is, the longer the relative distance is fixed, the problem of cable crosstalk. Such as the crosshairs that increase in the middle of category 6 lines.
3. Increase wire shielding. Add a shielding layer, such as a metal aluminum foil layer, to the outside of each core of the cable to improve the crosstalk between the wire pairs. This is also a common structural design method for Category 7 lines.
4. Control the production process. Such as the center of the insulation, tracking of the outer diameter, the twisting pitch, the pitched genome, the smaller the movement of the shaft, the crosstalk transmission process.
With regard to the crosstalk problem of communication data cables and related information in design, production, processing, and use, Zhaolong has continuously improved the cable technology and product performance through 28 years of research and manufacturing.
What is a DAC high-speed cable?
DAC high-speed cable (Direct Attach Cable) is generally translated as direct cable or direct-attached copper cable. It is usually a fixed-length cable assembly with fixed connectors at both ends, with ports not being able to be replaced and module heads and copper cables not being able to be separated. High-speed cables are accepted and used by more and more users due to their significant advantages such as high price-quality ratio, high performance, high speed, high composite, and low loss. They have become the first choice for high-speed data communication solutions. And they are widely used in storage area’s networks, data center and the connection between high-performance computers.
What are the advantages and characteristics of DAC high-speed cables?
It has become a preferred solution for users in short-distance application scenarios. It is widely used in data center’s interconnection scenarios such as SATA storage devices, RADI system scenarios, core routers, 10G or 40G Ethernet, etc.. In data centers, copper cables are generally used to connect servers and storage area’s networks. The most commonly used is Direct Attach Copper Cable (DAC), and among which passive copper cables are most particularly used. Since passive copper cables are of low price and of fast transmission speed, they have become the best solution for short-distance transmission. For example, 40G QSFP+ passive cable is one of passive copper cables. Because of its low power consumption, high efficiency, low cost and low latency, it is widely used in 40G LAN, HPC and SAN. And 40G QSFP+ passive cable is also suitable for flexible wiring; we can say that 1 SFP+ high-speed cable is equal to 2 SFP+ 10 Gigabit optical modules and 1 pair of OM3 10 Gigabit fiber jumpers.
What is the basic structure of DAC high-speed cable?
Our DAC high-speed cable mainly takes silver-plated conductors and foamed insulated core wires as materials while some manufacturers use special PTFE films instead of insulating materials, foamed PE. Because this cable has high requirements for materials and processes, there are currently very few manufacturers that can produce them. The method of shielding and total shielding make our high-speed cables have excellent attenuation performance, low delay and anti-interference, and have the capability of realizing high-frequency broadband transmission. Our high speed cables range from 30AWG to 24AWG, with various structures such as 2P, 4P or 8P. And it can be used in many different applications.
What is 400ZR?
400ZR, also known as 400G ZR, is a specification defined by the Optical Internetworking Forum (OIF). The specification uses a combination of the plans of Dense Wavelength Division Multiplexing (DWDM) and high-order modulation. Due to 400ZR, 400G can be transmitted on the interconnect (DCI) link of the data center. Its purpose is to ensure long-term and stable implementation based on single carrier 400G. This single carrier uses complex polarization multiplexing’s 16-level quadrature amplitude modulation (DP-16QAM) with a rate of approximately 60 Gbaud.