BACnet Driver Troubleshooting

The following table is designed to help you resolve issues while configuring and running the- BACnet driver.

Problem

Cause

Resolution

During a new installation, you are unable to configure or add a BACnet driver.

The PMON user account is set to an account without administrative privileges.

  • In SMC, change the original account to a PMON user account with administrative rights, and then configure the BACnet Driver.
  • After configuring the driver, change the PMON user account back to the original account.

    For more information, see Engineering Reference > Project Setup > SMC Troubleshooting > Troubleshooting Projects.

After trying to start the driver, the Manager Status is Failed, and the Network Status is Not Reachable.

The driver is not properly configured.

  • Follow the instructions for Configuring Basic Driver Settings in the Step-by-Step section.

The Manager Status is Failed, an alarm is generated, and the Device State is Not Reachable.

The device hosting the driver is disconnected.

  • Make sure the device hosting the driver is connected.

Exporting BACnet SC Keys to Troubleshoot Network Issues

BACnet SC uses transport layer security (TLS) to encrypt communication between devices, including the Desigo CC management station. This means that your network traffic cannot be read by any other party or device outside of the BACnet SC network, unless they possess a “key” file to read it. Should you need to analyze BACnet SC data to troubleshoot any device or network issues, you will first have to decrypt the traffic using the right key. Desigo CC allows you to export a key file that can be used for decryption, typically with a network analysis tool like Wireshark.

Prerequisites

Step-by-Step

  1. In System Browser, select Management View
  2. Select Project > Field Networks > [Your BACnet SC network name]
  3. Click the BACnet tab and open the Network Setting expander
  4. In the Export BACnet SC keys field, click the Enable button.
  5. After you click Enable, you will receive a message informing you that the project must be restarted in SMC, and that the keys will be written to the “\data\BACnetSC\" directory after the SC network reconnects
  6. Go to the Desigo System Management Console, and select Projects > [Your Project]
  7. Click Stop to stop the project, then click Start to restart it
  8. In Windows, visit [Your Project Directory]\data\BACnetSC\, where you will see the private key file in the format lws_x.log, where x is the driver number

When examining the traffic over the interface that contains your BACnet SC network, configure your network analysis tool to use this key.

For security reasons, when you have finished examining the traffic from your network, you should press the Disable button to stop exporting the key. The exported key file will remain in the directory; however because each secure network session creates a new key, upon session restart the exported key becomes invalid.