US Patent 7475328 Loop status monitoring apparatus

A loop status monitoring apparatus monitors a status of an arbitration loop that includes a plurality of devices and a switch that controls connections between the devices, has at least one of loop status detection data, primitive detection data, and frame count data, and includes a failure detecting unit that detects whether an initialization failure, which is a connection failure, has occurred during an initialization of the arbitration loop from the loop status detection data; and a device identifying unit that identifies, when the initialization failure is detected, a device with the initialization failure occurred from the primitive detection data or the frame count data.