If You Read Nothing Else Today, Read This Report on What Is Rs485 Cable > 자유게시판

Typical uses are very large networks, monitor and control of elevators, machinery, lighting, security, fire and alarm, access, cameras, military ground support, and much more. Use a wire or shielded wire to connect the GND ground of all 485 devices, so as to avoid the potential difference between all devices that affects communication. 1. Use shielded twisted pair wire and effectively ground it. 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. The most common cable type is Cat 5e-UTP (unshielded twisted pair) which may work over shorter distances in less demanding applications with low EMI noise levels. There are many applications of RS485 in weak current intelligent engineering, and the most common applications are in access control systems, BA systems, intelligent lighting systems, parking lot management systems, etc. With the continuous popularization of digital networks, RS485 is now less and less used in weak current applications. The method to eliminate differential mode interference is to add a bias resistor (matching resistance in the dome camera) to the circuit, and use twisted-pair wires; common mode interference is transmitted between the signal line and the ground, which is asymmetrical interference.

Differential mode interference is transmitted between two signal lines and belongs to symmetrical interference. RS-485 cables typically have two twisted pairs of wires for differential signaling, allowing for greater immunity to electromagnetic interference. The transmission speed of RS485 cables can vary depending on factors such as cable length, baud rate, and the quality of the cable itself. Twisted pair structure: Rs485 anti-interference cable has a twisted pair conductor structure. What communication protocols are supported by RS485? It transmits signals through the voltage difference between the two communication lines, so it is called differential voltage transmission. 6) What is common mode interference and differential mode interference? 2) The common communication failures with 485 bus structure are as follows? ● Carry out construction strictly in accordance with the 485 bus construction specification to prevent any fluke. ● 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. Carry a few converters with you so that you can rule out whether the quality of the converter is affecting the communication quality.

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, what is rs485 cable and a few 120 ohm terminal resistors. 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. When the connection is long, please use terminating resistors at both ends of the network, i.e., at the master and the farthest device. ● If the communication distance is too long, such as over 500 meters, it is recommended to use a repeater or 485 HUB to solve it. In this case, it is recommended to add an RS485 distributor. ● 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. R E Smith also provides several functionally identical units with different connectors and LEDs: ASC24R, ASC24W, RSFC24R, RSFC24W, and ASC24TS.

Both will work with RJ11 connectors and CBL03 cables. Circuits may be terminated on screw terminals, D-subminiature connectors, or other types of connectors. Multiple receivers may be connected to such a network in a linear, multidrop bus. 7) Under what circumstances should a terminal resistance be added to the 485 bus? Only when the 485 communication distance exceeds 300 meters, the terminal resistance should be added at the beginning and end of the 485 communication. 485- of the last 485 device to improve the communication quality. You'll need to determine how to set the address on the converter as well as figuring out what the address is on your RS485 device. Simply pull a line to the device alone, which can be used to rule out whether the wiring is causing the communication failure. I just needed to figure out a way to mount it and make it work correctly. Before debugging, make sure that the wiring of the equipment is correct and the construction conforms to the specifications. Please be patient as we make every effort to help you to resolve the issue.