Feature Guide: CAN Acquisition

Overview

The CAN Acquisition feature allows OxTS INS units to receive and log data from a vehicle’s CAN (Controller Area Network) bus. These signals can be viewed in real time using NAVdisplay, or analyzed later in NAVgraph.

Typical uses include:

• Recording vehicle parameters such as wheel speeds, steering angle, or throttle position

• Adding aiding data (e.g. wheel speed or ground speed sensors) to enhance navigation accuracy

• Synchronizing vehicle and navigation data streams

⚠️ Important: Always use a CAN isolator when connecting an INS directly to a vehicle’s CAN bus.

Configuration

Follow these steps in NAVconfig to configure CAN inputs:

Step 1 – Open the CAN Acquisition Tab

1. Power and connect the INS.

2. Launch NAVconfig and select the connected unit.

3. Navigate to the Interfaces → CAN Acquisition tab.

Step 2 – Load the DBC File

1. Click Load DBC File and select a valid CAN DBC file.

   • The DBC defines message and signal details for your vehicle’s CAN bus.

2. Once loaded, all available messages will appear in the table

Step 3 – Select Messages to Log

1. Tick the Enabled box beside each message you wish to log.

2. You can enable up to 12 CAN messages per configuration.

   • These selected messages are logged at the INS update rate (100 Hz or 250 Hz).

   • This logging rate is fixed and not user-adjustable.

Step 4 – Edit Signal Properties (Optional)

1. Click a message to view signal properties in the bottom table.

2. You can adjust:

   • Message Name

   • Signal Name

   • Units

Edits apply only to the INS configuration and do not modify the DBC file.

Validating CAN Acquisition Setup

After setup, confirm your CAN configuration is working correctly.

1. In NAVdisplay, ensure your data output is set to XCOM.

   • CAN data is only transmitted in the XCOM container stream (not NCOM).

2. Verify that the enabled CAN messages show live updates in NAVdisplay. If values remain static, check:

   • The CAN bus connection and isolator

   • Message IDs and scaling in the DBC file

Note: The XCOM data stream is higher bandwidth than standard NCOM. It is therefore recommended to use a modern laptop and enable High Performance mode to ensure smooth data transfer and logging.

Post-Processing

CAN acquisition data is recorded within the RD file during operation. To view this data in post-processing, simply process the file as normal in NAVsolve.

During processing, NAVsolve generates an XCOM file alongside the standard NCOM file. You can then open the XCOM file in NAVgraph to view and analyze the logged CAN data.