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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. 7) Under what circumstances should a terminal resistance be added to the 485 bus? The length of the branch line from the bus to each terminal device should be as short as possible, generally not exceeding 5 meters. Only when the 485 communication distance exceeds 300 meters, the terminal resistance should be added at the beginning and end of the 485 communication. RS-485 does not define a communication protocol; merely an electrical interface. RS-485 standard conformant drivers provide a differential output of a minimum 1.5 V across a 54-Ω load, whereas standard conformant receivers detect a differential input down to 200 mV. RS-485, also known as TIA-485(-A) or EIA-485, is a standard, originally introduced in 1983, defining the electrical characteristics of drivers and receivers for use in serial communications systems. The foreword to the standard references The Telecommunications Systems Bulletin TSB-89 which contains application guidelines, including data signaling rate vs. This includes speed control using Variable Frequency Drives (VFD) or inverters, as well as controlling simple PLC and HMI network systems.

● The manufacturer will do a lot of testing work for its supporting 485 converter, and will require the 485 converter manufacturer to carry out production and quality testing according to its fixed performance parameters, so it has better compatibility with access control equipment. ● No communication, no response. First, make sure that the computer notebook you carry with you is a device with normal communication, and use it to replace the customer's computer for communication. ● The system prompts that there is interference during communication, or the communication indicator keeps flashing when not communicating. 485- of the last 485 device to improve the communication quality. It is best to connect a 120Ω terminal resistor at both ends of the RS485 device. For on-site debugging, you must carry a few converters that can connect to long distances and multiple loads, a commonly used computer notebook, a multimeter to test the circuit break, and a few 120 ohm terminal resistors. If it is normal, it indicates that the serial port of the customer's computer may be damaged or injured. In multifunction instruments, not only the cables connected to the measurement, but also the RS485 serial port and the analog and digital inputs and outputs must be wired.

1. Ordinary twisted pair shielded cable STP-120Ω (for RS485 & CAN) one pair 20 AWG, the outer diameter of the cable is about 7.7mm. Suitable for indoor, pipeline and general industrial environment. 3. Armored twisted-pair shielded cable ASTP-120Ω (for RS485 & CAN) one pair 18 AWG, the outer diameter of the cable is about 12.3mm. It can be used in places with severe interference, frequent rodent damage, and lightning protection and explosion-proof requirements. 3964616. This connector basically swaps pins 2&3 on one side so you don't have to rebuild your cable. But before we dive deep into those SATA cable classifications, we need to have a look at what SATA actually means. Once you have selected the appropriate firmware, select the "??(O)" button. ● If there are too many loads, such as more than 30 units on a bus, it is recommended to use 485 HUB to solve the problem. ● Use scientific and reserved solutions for 485 bus projects with long lines and heavy loads.

Differential mode interference is transmitted between two signal lines and belongs to symmetrical interference. The 485 communication line is composed of two twisted-pair lines. Before digital instruments begin to operate, they must be set with measurement system parameters and communication parameters. Connecting analog instruments is very simple; you just need to connect the phase and neutral cables to the instrument. First you need to download the software. The first priority was to get the pool cleaned up and then figure out how to keep it that way. 3. Keep away from high-voltage wires when wiring, what is rs485 cable and do not bundle high-voltage power wires and signal wires together. • EIA/TIA-485 communication interface with low power requirements. Overall, RS485 cables are known for their robustness, reliability, and versatility, making them a popular choice for industrial automation, building control systems, and other applications requiring stable and secure communication over extended distances. Control and monitoring systems: A single pair of rs485 signal cable can connect up to 32 devices, with a signal transmission distance of up to 1200m. Therefore, using rs485 cables is an ideal choice for industrial control and monitoring systems, especially those with large-scale and high dispersion. RS485 industry Standard use requirements, so when the distance between each device line is relatively long, it is easy to cause problems such as signal reflection and anti-interference ability, which leads to a decrease in the reliability of the control signal.