Circuit for generating RS485 flow control signal by asynchronous communication

Abstract

The invention discloses a circuit for producing a flow control signal of RS485 by a sending signal of asynchronous communication. The circuit utilizes the sending signal of the asynchronous communication to generate the flow control signal of the RS485 to finish the control of an RS485 bus when an RS485 interface circuit is designed only with a transceiving signal of the asynchronous communication. In the circuit, the driving ability of the RS485 bus is strengthened and the effective communication distance is guaranteed through the active time sequence control to the flow control signal. The circuit has no delay conversion when applied to various conversion circuits.

Description

technical field [0001] Various monitoring and control systems using asynchronous communication technology are widely used at present. Applications include various automation control systems, security monitoring networks, intelligent building systems, medical instruments, etc. Background technique [0002] In the past, various monitoring and control systems widely used asynchronous communication technology, most of which adopted the RS232 standard. However, with the expansion of the communication range and the improvement of anti-interference ability, the RS485 standard using differential transmission technology has been more and more used. Therefore, there is a great market demand for converting RS232 to RS485 signals, or designing RS485 communication interfaces in products. Contents of the invention [0003] When designing an RS485 interface circuit, a flow control signal must be provided to the RS485 driver chip. Many asynchronous communication ports only send and rec...

AI Technical Summary

Problems solved by technology

Almost no delay in the conversion process when applied to various conversion interfaces

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