We occasionally receive questions regarding Incomplete IN Transactions or other downstream ghost packets in the capture. This is caused by the 1480A Analyzer capturing downstream packets sent to devices on other cable segments than the 1480A Analyzer is connected to. The USB Host Controller will broadcast downstream packets to all cable segments (ports) connected to the host controller, not only to the cable segment (port) the target device is connected to. This will show up in the trace as 'Incomplete' transactions like shown in the below image.

Image of ghost devices in the trace

These ghost devices can be filtered out via the 'Filter Protocol Items' dialog. In this case, filter out traffic from/to devices with Device ID = 4.