Retrieving status information from a remote device and corresponding host system

摘要

Method for retrieving status information from remote devices performed on host system connected via bus system comprising two signal lines (clock SCL, data SDA) terminated with resistors on host (RHC1, RHD0) and device (RRC0, RRD1) side. The method comprises the steps: activating sensing phase 100; sensing the two terminated signal lines (Clk SCL, Dat SDA) during sensing phase 100; determining operating state of the remote device based on sensing result; wherein first operating state representing a connected and powered remote device is detectable. The resistors can be pull up or pull down resistors. Signal lines can be terminated identically or inversely, to detect four different operating states, also via switchable resistors. Second state is unplugged device; third state is plugged but not powered device; fourth state is invalid state or connected, powered but not initialised device. The invention can work within low pin count bus environments.