Simcenter Testing Solutions Record Raw CAN Bus Data and Decode Offline!

Direct YouTube link: https://youtu.be/_aEBptlDyWo

Ready to perform a CAN Bus acquisition but don’t have a .dbc file immediately available to decode the data? No problem!

In Simcenter Testlab (previously called LMS Test.Lab) Version 16A and later it is possible to record the raw CAN Bus data stream and decode it later in a offline mode once the *.dbc file is available.

To record the raw CAN stream:

1. Open Simcenter Testlab Signature. In the Channel Setup workbook, choose the “CAN Settings” view from the dropdown in the upper right.

Figure 1: Go to the “CAN Settings” view.
 

2. Setup the raw acquisition as shown in Figure 2:

   A: Select the Can Device used for the acquisition.
   B: Enter a baud rate, for most vehicles this is 500000
   C: Set the device to “Passive”
   D: Click “Apply” to apply the settings.
   E: Go back to the standard “Channel Setup” view.

Figure 2: The “CAN Settings” workbook.
 

3. Back in the standard “Channel Setup” view, you will notice a new pane: “Digital Bus Channels” in the lower left of the screen.

In this area, there is an option to “Save Raw Data”. Check on this option. The raw CAN stream will be acquired.

Figure 3: The “Digital Bus Channels” pane appears in the Channel Setup workbook.
 

NOTE: Most SCADAS hardware is able to record raw CAN data for later decoding. However, Vector boxes will not support the recording of raw CAN streams. Vector boxes were primarily used with the Scadas III hardware before CAN was embedded in the XSI of the SCADAS Mobile / Recorder units, or the SYSCON, the CN4 card, or the SCADAS XS. Measuring OBDII channels is also not supported with Vector boxes.

Decode the raw CAN offline:

1. Replace the entire run into the Input Basket (replacing just the LDSF or RDDF is not sufficient). Right click on the run name and choose “Replace in Input Basket”.

Figure 4: Replace the entire run in the Input Basket.
 

NOTE: The LDSF contains the raw time data from the run. The RDDF contains the raw CAN Bus stream. The RDDF and LDSF are separate files, though they are stored in the same directory.

Figure 5: The raw CAN stream will be stored in an XSI-CAN file like the one shown above.
 

NOTE: If there is no RDDF called “Digital Bus Data” it means the raw CAN Bus was not recorded.

2. Time Data Selection workbook (see Figure 6):

A: Ensure the “Data Source” is set to “Input Basket”. Click “Replace” to import data.
B: Click the “Import digital bus channels” button (black arrow and two yellow lines).
C: Select the .dbc file corresponding to the CAN device.
D: It is recommended to change “Interpolation” from “Sample and Hold” to “Linear”.
E: Click “OK”.
F: New channels are created for all decoded CAN signals.
G: Save the decoded CAN Bus channels into the project by pressing the “Save As…” button. The data will be stored in the project and can be viewed in the Navigator workbook.

Figure 6: Create new channels for all decoded CAN signals.
 

3. The decoded CAN Bus data is saved into the throughput file of a new folder in the Navigator workbook.

Figure 7: The data is saved into the Throughput folder.
 

NOTE: Legislated OBDII signals do not get recorded in the raw can stream. They must be actively requested during acquisition. They are not broadcast on the CAN Bus by default.

Note that this feature is supported on the built-in CAN Bus interface on Simcenter SCADAS Mobile, Simcenter SCADAS Lab, and Simcenter SCADAS XS.

Figure 8: CANBUS interface on SCADAS Mobile
 

Recording raw CAN Bus is not available with the USB based Vector box used with SCADAS3.

That’s it! Enjoy the convenience of being able to save and decode the raw CAN stream!

Questions? Email scott.beebe@siemens.com or contact Siemens Support Center.

Simcenter Testlab Data Acquisition Links:

• Index of Testing Knowledge Articles
• Simcenter Testlab Signature
• Hands-free acquisition (almost)
• Capturing Transient Events in Simcenter Testlab
• Cool Channel Setup tricks for Triaxial Accelerometers
• Copy Channel Setup from One Project to Another?
• View Channel Setup from Desktop Navigator!
• Data Acquisition Based on GPS Location
• How to calculate a VECTOR SUM
• Tips and tricks for acquiring torsional orders
• CAN Bus Measurements
• Simcenter Testlab: Tips for Trouble-free CAN Bus Operation
• No more tach! Use OBDII to get engine and vehicle speed...
• Single Plane Balancing in Simcenter Testlab
• Measuring strain gauges in Simcenter Testlab
• Importing video into Simcenter Testlab Neo
• Correcting a bad calibration factor
• Simcenter Testlab Calibration

Simcenter SCADAS:

• Simcenter SCADAS Mobile and SCADAS Recorder Hardware
• Simcenter SCADAS XS: Everything you need to know!
• Simcenter SCADAS Cable Guide
• Simcenter Testlab Smart App Favorites!
• Simcenter Soundbrush
• Single Ended versus Differential Inputs
• AC versus DC Coupling
• How to use SCADAS T8 Thermocouple card?
• ICP versus IEPE versus Charge Accelerometers
• Long Cable Lengths and ICP Transducers