Sniffed Data Analysis

Use Sniffed in the RaceStudio 3 toolbar to manage and analyse recorded CAN-bus traffic. You can inspect frame identifiers and payloads, apply a protocol to decode channels, and follow their values through the recording. Offline analysis works with files on your PC; you do not need a device connected while examining them.

The recording database follows the same general arrangement as the RaceStudio 3 Analysis: filters and collections on the left, recordings in the main list, and an information preview. Its analysis window works with CAN frames and a time cursor rather than the lap-based layouts used for ordinary logger sessions.

Adding Sniffed Recordings

Recordings downloaded from a device in sniffer mode are added to the local sniffed-data library. Once a recording is present, the Sniffed button appears between CAN Protocols and Devices in the main toolbar.

If the button is not yet visible and your first recording was supplied as a file:

  1. Close RaceStudio 3.

  2. Copy the supported recording files directly into user/sniffed inside the RaceStudio 3 installation folder, creating that folder if necessary. The user folder is alongside 64, not inside it; files must be in user/sniffed itself rather than a subfolder.

  3. Restart RaceStudio 3. A recognised recording makes the Sniffed button available.

In the Sniffed database, press Import new sniffed file(s) to add recordings supplied as files. Select one or more files and confirm the import, or drop the files onto the recordings list. Import copies them into the local library and expands compressed XCZ files. RaceStudio 3 checks their format, asks before overwriting existing files, and reports files it cannot import.

The supported file types are:

  • .xck: an uncompressed AiM CAN recording;

  • .xcz: a compressed AiM CAN recording, decompressed when needed for analysis;

  • .csv: a CAN-frame recording in the CSV format supported by the sniffer;

  • .mf4: a CAN-bus logging recording in the MDF format supported by RaceStudio 3.

CSV and MF4 files must contain compatible CAN-frame data. A CSV table of ordinary channel values, or an MDF file containing other types of measurements, is not the same recording format.

Files with the same base name are grouped as one recording, including different format variants. Keep the recording names when copying or sharing them, and check existing names before replacing files in the library.

Finding and Organising Recordings

The database window has three areas:

  • the left column, for choosing a calendar entry, recent recordings or a collection;

  • the main list, for selecting recordings and opening, exporting or erasing them;

  • the preview, for examining information about the selected recordings.

The preview-position button offers Show Preview Right of DB, Show Preview Below DB and Hide Preview. Drag the dividers to adjust the space given to each area. These layout choices are remembered.

Filtering the Sniffed Database

Use All Sniffed and its calendar to choose a year, month or day. The calendar uses the date inside the recording; No date groups recordings without that information. Under Recent, choose Last 30 recorded, Last 30 opened or Last 30 added.

The search field filters by Logger ID, including part of an ID. Clear the search text to remove that filter. This search does not use the channel names or decoded values inside the recording.

Smart and Manual Collections

  • A smart collection stores a search rule and updates its contents as matching recordings become available. Click the options icon beside Smart Collections, enter a name and a Logger ID search rule, then confirm with OK. Use Edit Collection to change that rule.

  • A manual collection groups recordings you choose yourself. Add selected recordings using Add to Manual Collection in the row menu, or drag recording rows onto the collection in the left column. Create a collection with the options icon beside Manual Collections.

Use the collection’s options menu to edit or rename it, or choose Erase Collection to remove the collection while keeping its recordings. Within a manual collection, Remove from This Manual Collection removes the selected items from that collection and leaves the recordings in the library.

Previewing Sniffed Recordings

Select one or more recordings to populate the preview:

  • Info shows recording information such as Logger ID, firmware, recording date, bitrate, file format and size. Fields not supplied by the recording can be blank.

  • Frame statistics summarises frame activity when an XCK file is available. Statistics are not available in this preview for recordings stored only as CSV or MF4; those files can still be opened for analysis.

Opening and Playing a Recording

Double-click a recording to open its analysis tab. You can also select recordings and use Open selected sniffed file(s) for replay, or choose Open for replay from the row menu. Each recording opens in its own tab. If the recording is already open, its tab is brought to the foreground.

Here, replay means following the saved frames in the analysis window on your PC. The window starts playing at normal speed from the first frame.

  1. Press Pause to hold the cursor at the point you want to examine.

  2. Click or drag the cursor on the horizontal time bar to move to another point. Frame payloads, channel values and statistics follow that cursor.

  3. Press Play to continue from the cursor. At the end of a recording, Play starts again from the beginning.

  4. Enable Loop if you want playback to repeat; disable it to stop at the end.

Dragging the time cursor temporarily pauses playback. If it was playing before the drag, it resumes when you release the mouse. The time bar also indicates parts of the recording without CAN frames. Loop is a shared setting for the recording-analysis tabs.

The duration button offers 1 s, 2 s, 5 s and 10 s. It sets the period immediately before the cursor used for frame statistics and channel graphs. For example, with 2 s selected, the graphs describe the two seconds leading up to the cursor.

Reading and Filtering CAN Frames

A CAN frame contains an identifier and a payload of data bytes. The analysis window can organise the frames in two ways:

  • By ID groups frames by identifier and shows the payload at the cursor together with statistics for the selected time window.

  • By time shows the most recent frames first, up to the last 100 messages at the cursor.

Use View to display bytes as Hexadecimal, Binary, Decimal or Characters. Choose the representation that makes the byte or bit changes you are investigating easiest to see.

Important

Changing the organisation between By ID and By time clears the currently applied channels. Apply the protocol again if needed after switching. The recording file remains available.

Use the row markings with Hide unwanted or Show only wanted to focus on particular frames. Clear filters clears those markings and returns to Show all. The analysis search field matches displayed identifiers and channel descriptions, including names and byte order. This is separate from the Logger ID search in the recording database.

Applying a Protocol to the Recording

A protocol describes how channel values are encoded in the CAN payload. If you know the protocol used by the recorded equipment:

  1. Choose Apply protocol to open Choose ECU Protocol.

  2. Find the manufacturer and model. The list distinguishes AiM protocols from your custom protocols, even when their names match.

  3. Select the protocol and confirm. Inspect the resulting channels against the recorded frames and the equipment’s expected behaviour.

Choosing a different protocol rebuilds the channels in the window. Choosing the same protocol again preserves the current channel changes.

Note

The sniffer displays decoded raw values with a factor of 1 and an offset of 0. Do not interpret them as physical units solely because the selected protocol uses those units elsewhere in RaceStudio 3. Check the encoding and conversion before drawing conclusions about a measurement.

Using Protocol Wizard

If the protocol is not known, open Protocol Wizard. It compares identifiers found in the whole recording with those used by available protocols, and lists candidate matches with counts and percentages.

Choose a candidate and confirm to apply it. A high identifier match is a starting point: check that the decoded values and their changes agree with the recorded equipment. The match considers the entire recording, not just the seconds before the current cursor.

Inspecting Decoded Channels

Click an unprotected channel’s bit block to add or remove it from the highlighted channels on the right. These channels can be shown as current values or as graphs over the time window before the cursor.

Use the options icon on a highlighted channel to choose Switch to graph or Switch to value. Switch all to graph and Switch all to value apply the choice to all highlighted channels. Graph scales follow the available data; No data means there are no samples in the current time window.

Protected channels can show their names and values without exposing their bit definitions. They cannot be edited or added to the highlighted-channel graphs.

Saving Highlighted Channel Sets

The channel-set toolbar button provides Save highlighted channels as a new set…, Load set, Overwrite set and Delete set.

Save a set after choosing the channels you want to inspect and their value or graph modes. Loading a set replaces the current highlighted selection. Apply the appropriate protocol first: loading a set does not apply a protocol, and channels absent from the recording’s current channel definitions cannot be shown.

Building a Custom Protocol from Sniffed Data

To define a channel yourself, double-click a free bit in a frame, or choose Add Channel from the frame row menu. Double-click an existing unprotected channel to open its definition in the CAN Builder.

After defining and checking the channels, choose Create new custom CAN protocol to save them in Custom Protocols. Protected channels are excluded from the new protocol. See Custom Protocols for managing custom protocols and using them in a device configuration.

Exporting and Erasing Recordings

Select recordings in the database and press Export selected sniffed file(s). The menu offers:

  • Export, to copy the recording files for sharing or archiving;

  • Convert to MF4, to create an MF4 CAN-bus recording for each selection. When an MF4 file is already present, it is copied; otherwise RaceStudio 3 converts the available recording.

The same commands are available from the recording row menu. Import exported files into the other RaceStudio 3 installation to analyse them there.

The export destination is AiM-RS3-Exports/Sniffed under your Windows Documents folder. Check this folder for the exported files, even if Windows Explorer does not open automatically.

Erase selected sniffed file(s) asks for confirmation before deleting the selected recordings from the local library. Erasing a recording removes its stored format variants, so use Export first if you need to keep a copy. To change a manual collection’s membership, use its remove-from-collection command instead.

Example: Follow a Changing CAN Value

  1. Import a compatible recording and locate it using the calendar or Logger ID search.

  2. Open it for replay and pause near the event you want to investigate.

  3. Choose By ID, then apply the known protocol or inspect candidates with Protocol Wizard.

  4. Highlight an unprotected channel and choose Switch to graph.

  5. Select a suitable time window and move the cursor through the event. Compare the channel graph with its frame payload as the cursor moves.

  6. Save a highlighted-channel set if you want to return to the same selection later.

If the expected channel is missing, check the protocol, frame filters and search text. If a graph shows No data, move the cursor to a part of the recording containing that channel’s frames and check the selected time window.