使用asammdf结合DBC提取CAN总线日志无输出问题排查

7月12日更新：问题根源在于MDF文件未关闭，调用mdf.close()即可解决该问题。

我尝试使用Python的asammdf库结合DBC文件从MDF文件中提取CAN总线日志数据，已验证源MDF文件包含CAN通道与消息，但提取后得到的MDF对象中似乎没有任何CAN通道或消息。

使用的代码 #

from asammdf import MDF

# Load MF4 file
file_path = r'somepath'
mdf = MDF(file_path)

# Define the path for DBC files
pathdbc = r'dbcpath'

# Define the databases dictionary
database_files = {
    "CAN": [
        (pathdbc + "ch1.dbc", 1),
        (pathdbc + "ch2.dbc", 2),
        (pathdbc + "ch3.dbc", 3),
        (pathdbc + "ch4.dbc", 4),
        (pathdbc + "ch5.dbc", 5)
    ],
}

# Extract bus logging data using the DBC files
print("Extracting bus logging data using the provided DBC files...")
try:
    extracted = mdf.extract_bus_logging(database_files=database_files)
    print("Extraction successful.")
except Exception as e:
    print(f"Extraction failed: {e}")

# Function to list messages in a specified CAN network
def list_messages_in_can_network(network_id):
    can_networks = extracted.bus_logging_map.get('CAN', {})
    if network_id in can_networks:
        messages = can_networks[network_id]
        print(f"\nCAN Network {network_id}: {len(messages)} messages")
        for message_id, index in messages.items():
            print(f"Message ID: {message_id}, Index: {index}")
    else:
        print(f"No messages found for CAN Network {network_id}")

# List the names of CAN networks after extraction
def list_can_networks_after_extraction():
    can_networks = extracted.bus_logging_map.get('CAN', {})
    print(f"Number of CAN networks after extraction: {len(can_networks)}")
    for network_id in can_networks.keys():
        print(f"CAN Network ID after extraction: {network_id}")

# List messages in CAN Network 4
network_id = 4

# Run the functions
list_can_networks_after_extraction()
list_messages_in_can_network(network_id)

输出结果 #

提取总线日志数据中...
提取成功。
提取后CAN网络数量：0
未找到CAN网络4的消息

已尝试的操作 #

• 验证MDF文件结构，确认其包含CAN数据；
• 检查DBC文件，确保文件正确且可访问；
• 确认DBC文件包含预期的消息定义。

核心疑问 #

为何extract_bus_logging函数无法在提取后的MDF对象中找到CAN通道或消息？如何正确提取并将DBC文件映射到MDF数据？

内容的提问来源于stack exchange，提问作者Ganesh Narasimhan