Self-detecting and self-recovery RS485 communication circuit

The utility model provides a self-detecting and self-recovery RS485 communication circuit comprising a first communication circuit comprising a first 485 chip and a second communication circuit comprising a second 485 chip. The eighth pins of the first and the second 485 chips are connected to a collector of a PNP audion, the sixth pin and the seventh pin of the first 485 chip are respectively connected to an A terminal and a B terminal of a 485 bus, the seventh pin and the sixth pin of the second 485 chip are respectively connected to the A terminal and the B terminal of the 485 bus. The sixth pin of the 485 chip is connected to the collector of the PNP audion through a pull-up resistor. A base of the PNP audion is connected to a 485 communication control terminal, an emitter of the PNP audion is connected to a power source, the seventh pin is connected to a collector of a NPN audion through a pull-down resistor, a base of the NPN audion is connected to the collector of the PNP audion, and the emitter of the NPN audion is grounded. The self-detecting and self-recovery RS485 communication circuit can automatically switch work states of two communication circuits and maintain normal communication.