rs-485 bus anti-collision method, interface chip and communication network thereof

Abstract

The application discloses an RS-485 bus anti-collision method, an interface chip and a communication network thereof. The method includes: the DE pin of the RS-485 interface chip is a high level logic "1", and the REN pin is a low power Under the situation of flat logic "0", sample the input signal of the transmitter in the described RS-485 interface chip, and delay output, obtain the first sampling value; To the receiver in the described RS-485 interface chip Sampling the output signal of the output signal to obtain the second sampling value; judging whether the first sampling value is consistent with the second sampling value; if consistent, connecting the output terminal of the receiver to the RS‑485 interface chip On the contrary, fix the RO pin to low level logic "0", and turn off the transmitter, so as to solve the emergency situation of the slave but not in time under the premise of avoiding signal conflict on the bus Issues reported to the host.

Description

technical field [0001] The invention relates to the technical field of communication, more specifically, to an RS-485 bus anti-collision method, an RS-485 interface chip and an RS-485 communication network. Background technique [0002] RS-485 supports a half-duplex communication mode with one master and multiple slaves. In the RS-485 communication network, the master polls the slaves on the bus one by one, and the slave responds to the master according to the polling mechanism to complete the communication, thus avoiding the situation caused by multiple subjects in the RS-485 communication network being in the sending state at the same time. Conflict of signals on the bus. However, this anti-collision mechanism has the following disadvantages: [0003] Since the slave machine does not have the initiative to send permission, even if the slave machine needs to report to the host machine in an emergency, it must wait for the host machine to query the slave machine according ...

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Problems solved by technology

[0004] In view of this, the present invention provides an RS-485 bus anti-collision method, an interface chip and a communication network thereof, so as to solve the problem that the slave cannot report to the master in time when there is an emergency on the premise of avoiding signal conflicts on the bus

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