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

System Manager is in Engineering mode
A BACnet SC network has already been created and is connected

Enabling BACnet Key Export

In System Browser, select Management View
Select Project > Field Networks > [Your BACnet SC network name]
Click the BACnet tab and open the Network Setting expander
In the Export BACnet SC keys field, click the Enable button to begin key log export.

Accessing and Using the BACnet Key Log File

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 new session keys. Past exported keys will remain in the export file. However, once a new session is created, all past keys are invalidated and no longer able to decrypt BACnet S/C traffic.