The main function of the 485 converter is to convert a single-ended RS-232 signal into a balanced differential RS-485 or RS-422 signal. Due to long-distance information transmission and strong anti-interference ability, rs485 converters are widely used in security communication and other fields. However, users often encounter signal interference. So, what causes the rs485 converter signal to be interfered?

1. Matching interference, which mainly comes from unreasonable system load matching. For example, the signal line is too long, too many (long-distance) star wiring, too much load, no system matching resistance, etc., which cause the system to work well and fail to work stably.

2. Strong common mode interference. This situation is often caused by the direct or indirect grounding of the receiving equipment at different locations, causing the communication between the signal line and the “equipment ground” or “the equipment digital ground” (usually 50 Hz) Caused by excessive signal. The performance reception is sometimes absent, or even unreceivable all the time. What’s more, data reception cannot be realized if the distance between the receiving and sending is one meter.

3. Hardware failure, usually because there is a history of high voltage in the line (lightning strike, leakage), causing problems with the rs485 converter chip of individual equipment in the system, affecting the overall reception.

4. Line faults, such as a local short circuit or a broken circuit in the signal line, often make the system work locally or work normally, but the work is unstable.