Shocking Information About What Is Rs485 Cable Exposed > 자유게시판

Because it may be used at high speeds, over long distances, in electrically loud settings, and with multiple devices on the same bus, RS-485 is a good choice for most serial interface applications. It is also an ideal choice for industrial equipment use due to its high speed, reliability and safety. It is unquestionably an ideal choice for industrial equipment use due to its high speed, reliability, safety and versatility. Ordinary twisted-pair cables can be used in general occasions, and shielded coaxial cables can be used in environments with relatively high requirements. 1. Ordinary network cables have no shielding layer and cannot prevent common mode interference. The use of shielded twisted-pair cables helps to reduce and eliminate the distributed capacitance between the two 485 communication lines and the common mode interference generated around the communication lines. The specifications of the shielded twisted pair used are related to the distance of the 485 communication line and the number of connected devices, as shown in the following table. If there are many load 485 devices, the wire impedance is not up to the standard, the wire diameter is too thin, the converter quality is poor, the equipment lightning protection is complicated, and the baud rate is increased.

In fact, not all 485 converters can be equipped with 128 devices. The connection method of the 120Ω matching resistance of the dome terminal is as follows: The 120Ω matching resistance of the dome terminal can be connected by the dial switch on the chassis of the dome. Industrial sites often need to collect multi-point data, analog signals or switch signals. RS-485 adopts half-duplex working mode and supports multi-point data communication. Serial communication also has a deterministic behaviour to avoid collisions of data packets, making it more reliable for a linkage system with many devices. The communication line should be as far away as possible from interference sources such as high-voltage wires, fluorescent lamps, etc. When the communication line cannot be avoided from interference sources such as power lines, the communication line should be perpendicular to the power line, not parallel, and cannot be bundled together, and use high-quality twisted-pair cables.

Common-mode interference will increase the above-mentioned common-mode voltage. 12V. If it exceeds this range, the communication will be affected, and the communication interface will be damaged severely. Some people say that the 485 bus can carry 128 devices for communication. The star structure will produce reflected signals, which will affect the 485 communication. The RS485 network must be designed as one line with multiple drops, not as a star or ring topology. That is, a bus is used to connect each node in series, and ring or star networks are not supported. The condition is that the communication wire is high-quality and meets the standard, the baud rate is 9600, and only one 485 device is loaded, so that the communication distance can reach 1200 meters, what is rs485 cable so the actual and stable communication distance of the 485 bus is usually less than 1200 meters. In theory, the longest transmission distance of RS485 can reach 1200 meters, but the transmission distance in practical applications is shorter than 1200 meters.

According to the 485 bus structure theory, under the premise of an ideal environment, the 485 bus transmission distance can reach 1200 meters. Generally, there are three levels of 485 chip load capacity-32 units, 128 units and 256 units. Generally, RS485 bus is used. How many devices can be connected to a bus? 2. It is not allowed to use a network cable with a wire diameter that is too thin, which will reduce the transmission distance and reduce the equipment that can be connected. What is a rs485 cable? This converter converts a USB port to not only RS485 but also RS232 and TTL, making it more versatile. You can find out more about the differences between RS485 and RS232 here. RS232 is more than able to perform for a short distance and low data speed requirements. Through appropriate programming and configuration settings within the central control system, relevant flow measurement data can be read from the flowmeter.