短路故障是RS485总线的常见故障，其危害较大，容易造成总线控制芯片的损坏。RS485总线一般通过发送检测报文来判定总线工作是否正常，该类方法的反应较慢，且不能避免接口电路的损坏。本文提出了一种基于电流检测的短路故障检测方法，它可以实时在线检测分支电路的短路故障，从而可立即屏蔽掉故障分支点，避免短路故障进一步损坏系统。

Short circuit failure is a common and harmful fault of the RS485 serial bus, which easily brings great damages to the serial bus controlling chips. Generally, detectable packets are sent to determine whether the RS485 serial bus works well or not. However, this method responds slowly and can not avoid damaging the relevant interface circuit. A novel detection technique for short circuit failure based on current detection is presented in this paper. It can detect the short circuit failure of the branch circuit online, and can shield the branch fault point immediately, which prevents short circuit failure from damaging the systems further.