Setting Custom Baud Rates on NI-XNET Devices

This article explains how to configure a custom baud rate for CAN or CAN FD communication using NI-XNET. You can either define the baud rate in the NI-XNET Database Editor or apply it programmatically in LabVIEW™ using interface properties.

Before proceeding, ensure you have:

• A valid NI-XNET database file
• NI-XNET hardware 
• NI-XNET driver installed
• LabVIEW (if performing programmatic configuration)

Configure Custom Baud Rate in NI-XNET Database Editor

1. Launch NI-XNET Database Editor.
2. Open your database file.
3. Select the CAN Cluster you wish to modify.
4. In Cluster Properties, select Custom from the Preset Baud Rate drop-down menu.
5. Configure the custom baud rate parameters in the available fields.
   1. Calculate timing values based on a 40 MHz clock (Time Quantum is 25 ns).
   2. Adjust values if migrating from hardware with a different clock frequency. For example, if parameters are based on 80 MHz hardware, divide the values by two.
   3. Account for hardware offsets where applicable. For example, if you need a BRP of 2, configure it as 1 because the hardware adds 1 internally.

7. Save the database.

Refer to Interface:64bit Baud Rate and Interface:CAN:64bit FD Baud Rate for a more detailed explanation of the Bit Timing Registers.

Configure Custom Baud Rate Programmatically in LabVIEW

1. Open your LabVIEW block diagram.
2. Place a property node:
   1. Right-click the block diagram and navigate to Measurement I/O>>XNET>>Session Node.
3. Select the appropriate property on the node:
   1. For CAN, select Interface>>64bit Baud Rate
   2. For CAN FD, select Interface>>CAN>>64bit FD Baud Rate
4. Copy the hexadecimal value from the custom baud rate dialog in the database editor.
5. Create a constant or control and wire it to the property node.

6. Convert the value to hexadecimal if needed. 
   1. Right-click the constant or control
   2. Select Display Format
   3. Choose Hexadecimal in the Numeric Constant Properties window.