I have questions regarding RS485 communication; I hope experts can provide some guidance
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Regarding RS485 communication: How to connect shielded twisted pair to the PLC terminals? Why is the signal transmission failing now after the connection was established? Whether the twisted pair shielding layer needs to be grounded, and an introduction to the grounding methods.
The issues you mentioned are all the most basic configurations in communication – how could there be any mistakes? ! The configuration is also different, right? Your question lacks clarity; it’s full of ambiguity. How can anyone give a clear answer?
Hehe. RS485 uses just two wires; I suspect the wires are connected incorrectly. Just swap them around, and that’s it. . No communication is possible; it has absolutely nothing to do with whether shielding or grounding is in place. Answer completed.
Cables have only a positive and negative polarity; if communication fails for some other reason, it has nothing to do with the cable at all. The configuration and communication software settings need to be taken into account. For example, the communication module and drivers, port selection, whether the baud rates on both ends are the same, whether the main address being used is correct, wiring methods and cable length, etc. 485 communication has distance requirements
Should the communication interface on the PLC be left as such or connected to terminal blocks? If a communication interface is used, you’ll need to create connectors (9-pin or 15-pin, etc.); with terminal blocks, wiring can be done directly. If communication still doesn’t work, use modscan to determine where the problem lies.
Hello, the communication mode is set to MODbus in RTU mode, with a baud rate of 9600 and address 23
Two ordinary cables are connected directly to the terminals.
You’ve provided too little information. Please describe in detail your device, its configuration, communication software settings, and so on, so that we can see if anyone can help you
The communication mode is set to MODBUS in RTU mode, with a baud rate of 9600 and address 23
Distance can be ruled out; 300 meters. The port selection should be correct. The communication driver cannot be determined.
In order: field panel, cabinet terminals, PLC cards