characteristic impedance Z0 of the transmission line cable. The RS-485 is recommended to use a 120 Z0 cable, so each end of the cable is usually used 120 resistance for end-to-end connection.
Figure 4: RS-485 end-to-end using common mode noise filter.
Applications in a noisy environment often use two RC low-pass filters to replace these 120 resistors to enhance the filtering of common-mode noise (see figure 4 ). It is worth noting that the resistance values of the two filters should be equal
). Note that the IP addresses of the two APS must be in the same CIDR Block and the same channel can be used to achieve wireless connection and resource sharing between the two wired LAN networks, or expand the wired network. It should be noted that both APs adopt oriented antennas.
Opinion 2: Use optical fiber
Many netizens have agreed to this solution, because the current price of fiber optics is also more than 10 pieces per meter, and the cost of pulling fiber cables between two points is no
work of other nodes;G. Twisted Pair wires are generally not installed outdoors. When a small part is installed outdoors, the casing should be installed in the outdoor part;H. Select the eight-core twisted pair wires. When you install the connectors on your own, the eight wires should be installed properly. Do not install only four wires or cut off the other four wires.Iv. Network Device InstallationHub InstallationA. the hub should be installed in a dry and clean room;B. The Hub should be insta
frame can be installed with RJ45 modules and fiber optic connectors.
The module can be used on both the Panel and distribution frame.
Based on years of experience, IBM has found that in the Integrated Wiring System, due to the constant changes in customer requirements, there are often some deviations between design and construction, especially some major projects, these results in a waste of time and cost for the entire project. If some structured de
termination resistor.Figure 2 shows an example of the SN75LBC176A transceiver Unit load calculation. Because the device integrates the drive and receiver together to form the transceiver (that is, the driver output and receiver inputs are connected to the same bus), it is difficult to obtain the drive leakage current and receiver input current separately. For ease of calculation, the receiver input impedan
certain share of the market at a low price. However, due to the low network transmission rate of the 10 Mbps ISA plug-in Nic and occupying a large amount of CPU resources, only applicable to LAN with low speed requirements. Therefore, we recommend that you use a 100 Mbps PCI plug-in or a 10 Mbps/Mbps adaptive Nic, Which is inexpensive and can be adapted to a large number of users, an application environment that transfers large amounts of data online and requires multimedia information.
When se
Master the high-end switch cascade to instantly become a master of the network, previously introduced the relevant knowledge. After the publication of the stack and cascade of switches, we have received a number of emails from many readers to discuss with us about the cascade of switches. So we will introduce some related content about high-end switch cascade.
High-end switch cascade: optical transceiver connection
When optical cables are used for cab
unplug the twisted pair cable, which does not affect the work of other nodes;G. Twisted Pair wires are generally not installed outside the room. When a small part is installed outside the room, casing should be installed in the outdoor part;H. Select the eight-core twisted pair wires. When you install the connectors on your own, the eight wires should be installed properly. Do not install only four wires or cut off the other four wires.
Iv. Network Device Installation
Hub InstallationA. the Hub
products of the information panel will also provide a square dark box) 2. Super Five class 4 pair shielded twisted pair cable In such a home environment, a variety of power lines criss-cross, microwave ovens and other electrical appliances work will also have electromagnetic interference, the summer thunder and lightning weather will often patronize such a single-family villa. Therefore, we choose to have the electromagnetic protection of super five type shielded twisted pair. (Figure 1) 3. Su
, 100 pairs, 300 pairs, 900 pairs of wall mounted types, and from the main distribution frame between the main equipment to the distribution frame between each distribution line, no matter the connection trunk or horizontal cable, all use this distribution frame. the advantage of the 110 fish bone distribution frame is its small size, high density, and low price. It is mainly used together with the 25/50/100 pairs of large logarithm cables. Its disadvantage is that it is troublesome to connect t
A lan is to connect individual computers or terminals using networks to exchange information and share resources according to certain protocols. Commonly used network cables include twisted pair wires, coaxial cables, and optical fiber cables. Twisted Pair wires can be divided into shielded twisted pair wires (STP) and unshielded twisted pair wires (UTP) based on whether they are added with the screen layer of a wire mesh ). Most local networks use unshielded twisted pair wires (UTP-unshielded t
Light Cat is "optical modem", refers to the optical Ethernet signal into other protocol signal transceiver equipment, but also plays the role of modulation and demodulation. The optical cat is also known as a single port optical transceiver, which acts as a relay transmission device for the local network, and is suitable for the optical terminal transmission equipment of the base station as well as the leas
packets are no longer differentiated on the DSLAM device after they are uplink through the IAD, and are directly passthrough to the broadband network bearer network. voice and data are connected to the voice and data services through their respective IP address headers. This solution is suitable for applications of families or small companies that only support twisted pair wires;
IAD is connected directly to the downstream RJ45 port of the RTU, and t
data, the MAC protocol can determine whether data can be sent in advance. If data can be sent, it adds some control information to the data, and finally sends the data and control information to the physical layer in the specified format; when receiving data, the MAC protocol first checks the input information and determines whether a transmission error has occurred. If there is no error, the control information is removed and sent to the LLC layer. Ethernet MAC is defined by IEEE-802.3 Etherne
the electromagnetic principle: it can be considered that the interference signals of the two signal lines are of the same phase and equal amplitude. After the two lines are combined, they both resist external interference and prevent themselves from interfering with others. Twisted Pair wires are commonly used.Most local networks use Unshielded Twisted Pair wires (UTP-Unshielded Twisted Pair) as the transmission medium for cabling. The network cable consists of a long Twisted Pair wires and
Directory
Directory
Summary
Introduced
Contikimac
1 Contikimac Timing
2 packet detection and fast sleep
3 Phase Lock Transmission
Realize
Evaluation
1 Micro Benchmark
2 Network Power consumption
Related work
Summarize
Reference documents
SummaryTo reduce system power consumption, a low-power wireless device must shut down the radio as much as possible, but in order to receive communication messages
whether the data can be sent, if it can be sent to the data with some control information, and finally the data and control information in the specified format sent to the physical layer, when the data is received, the MAC protocol first to determine the information entered and whether transmission error occurred, If there is no error, the control information is removed and sent to the LLC layer. Ethernet MAC is defined by the IEEE-802.3 Ethernet standard.The physical layer PHY is a physical in
wire breaker instead, after all, no-blade wire breaker generally uses a hexagonal design, which can effectively prevent minor cables from being damaged when it is used for wire stripping. On the contrary, when using a blade wire breaker to create a network cable, the sharp blade will cut the skin of the cable accidentally, which brings a fault risk to the efficient communication of the network in the future.
Optical module, reasonable connectionThe so-called optical terminal module is the conne
Port
The AuI port is the interface used to connect to the coarse coaxial cable. It is a "d" Type 15-pin interface, this is one of the most common ports in the ring or bus network. The router can connect to the 10base-5 network through a coarse coaxial cable transceiver. But more is the use of external transceiver (AUI-to-RJ-45), to achieve the connection with the 10base-t Ethernet. Of course, you can also
used normally, the general router has a control port "console ", it is used to connect to a computer or terminal device and configure a router through specific software. Next, let's take a look at the router's LAN and WAN connection ports.
1. LAN interface
According to the interface name, we can see that these interfaces are mainly used to connect routers and LAN, because the LAN type is also diverse, therefore, the LAN interface type of the router may be diverse. Different networks have di
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.