PD Logging tab (add-on feature)

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PD logging tab view

PD logging is a software add-on feature enabling capture, logging, and decoding of USB PD communications on all USB-C ports of the hub, including power negotiations and timing. At the top of the panel are logging controls and port selection toggles.

Stop - stops logging

Import - imports a CSV log file

Export - exports a CSV log file (stop logging before export)

Clear - clears the PD log

Port toggles - select which ports to monitor (can only change toggles when logging is stopped)

Show graph - when checked, clicking on an event pops up the Port Plot graph window and highlights the corresponding PD packet. Clicking on a yellow PD message in the port plot highlights the corresponding message in the log

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Graph view with highlighted PD packet

Below these controls is the PD packet log. The left axis is the row number, which resets when the log is cleared. Columns can be filtered by clicking the filter icon (carat icon) on the column headings:

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PD packet log headings

Time - clicking on this heading cycles among time references:

  • Hub time (s) - time since the hub powered on

  • App time (hh:mm:ss) - time since the HubTool App was launched

  • System time (yyyy.MM.dd hh:mm:ss:zzzz) - date and time

Port - ports 0-5, Control, or Power C

<-> - message direction - RX, TX, or ‘-’ (none)

Spec - USB PD version

SOP* - “Start Of Packet”

  • SOP - for messages between source and sink

  • SOP’ - for messages to the cable connector closest to the downstream-facing port (DFP)

  • SOP” - for messages to the cable connector closest to the upstream-facing port (UFP)

Power - sink, source, none

Data - UFP, DFP, ‘-’

ID - message ID, (0 – 7), increments with each new message. Acknowledgements should match message ID

Event type - description of the event

Packet type

  • Control - short messages that typically require no data exchange

  • Data - messages contain data objects that are transmitted between devices

  • Extended - data messages with larger data payloads

Message type - description of message

Raw - raw PD message (hexadecimal)