What is a straight line
Straight-through cable is a commonly used computer-to-switch connection, and the line sequence suppressed at both ends should be suppressed according to the t-568b method. The cross-over cable is a commonly used computer-to-computer direct connection line. One end is pressed according to t-568b, and the other end is pressed according to t-568a. And these two methods of suppression I mate are called twisted pairs
The following teaches the production method:
Twisted pair is a crystal head RJ45. There are two ways to play, one is 568A, the other is 568B.
Standard 568A: orange-white--1, orange--2, green-white--3, blue--4, blue-white--5, green--6, brown-white--7, brown--8;
Standard 568B: green-white--1, green--2, orange-white--3, blue--4, blue-white--5, orange--6, brown-white--7, brown--8.
What is 2.4g wireless module?
2.4g line module operating frequency in the range of 24400-2484mhz, can communicate through the scanning protocol, air rate up to 1Mbps, output power up to +4dBm, the module has the advantages of low power consumption, cost-effective. Movingcomm's current 2.4g antenna modules are: IOT04, IOT05, IOT09, IOT18, IOT60, etc. Users can choose a variety of modules with a transmission distance of 50-500 meters according to cost considerations.
Second, the role of 2.4g wireless module
Function 1, for the formation of a star topology wireless communication network, and must be a multi-point star topology, some extraordinary places need wireless communication. On the one hand, the transmitting and receiving module is cheap, and the cost of forming the star topology is relatively low. On the other hand, the transmitting and receiving module can adopt the modular design, which is small in size, easy to use and easy to integrate. For the wireless network with low communication speed and close distance, the transmitting and receiving module is very practical.
Function 2, for wireless multi-channel (parallel) control. Such as complex remote-controlled robots, some places require multi-channel (parallel) control. One method is to use the receiving module to directly connect to the decoder, and then connect to the relays and other electronic components to drive the subsequent controlled object; the other method is to use the receiving module to connect to the single chip microcomputer, and after the data is disposed of, the single chip microcomputer is connected to the relays and other electronic components to drive the subsequent controlled object. Usually a pair of transmitting and receiving modules can achieve up to six parallel wireless control, if the required number of channels is greater than six, you can use multiple pairs of transmitting and receiving modules, and work at the same time to meet the actual needs.
Function 3, used for general serial port, RS232 antenna data transmission, there are usually many control instruments and equipment using serial port, and communication with these devices must meet the requirements of serial port. In some extraordinary places, when the industrial control site must use the antenna transmission mode, it is natural to choose the transmitting and receiving modules mentioned in this article, but it must be explained here that to use this communication mode, the corresponding software must be prepared at the transmitting end and the receiving end respectively to achieve the conversion of file formats, in order to achieve the purpose of wireless communication, if the communication system is full-duplex. It can be achieved by using two pairs of transmitting and receiving modules, working simultaneously.
Third, 2.4g wireless module application field
2.4G wireless module is widely used in wireless health sports products, wireless mouse and keyboard, product information push, wireless remote sensing, wireless ranging system, alarm security system, smart home, toy control, tire pressure monitoring and other fields. With the 2.4G wireless module, all the whole house wireless smart home can be linked together, you can control all the smart home devices through the link of the network, and then you can control the switch of all the whole house wireless home, adjust the brightness of the lamp, adjust the rise and fall of the curtain, etc., through the continuous innovation of technology, The whole house wireless smart home can be controlled by a small white robot voice, can be controlled by a smart scene panel, can be controlled by sensors and so on.
Four, 2.4g wireless module how to choose antenna
In general, the 2.4g wireless module requires an impedance of 50 ohms, a red wire used with 2.4g, a 2.4g folded rod antenna, a 2.4g gold-plated straight head rod antenna, a 2.4g gold-plated elbow rod antenna, and a 2.4g small suction cup antenna. These antennas are special antennas designed for 2.4g wireless communication system, antenna standing wave ratio performance is good, small size, clever structure, easy installation, stable performance, with good anti-vibration and aging ability.
2.4G Router Module,M2 Wifi Module,2.4 Ghz Wifi Module,Mini Wifi Module
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