要通过 ZLG USBCAN-Ⅱ+ 设备使用 Python 发送和接收 CAN 报文，需要调用 ZLG 提供的动态链接库（DLL），通常是 `ControlCAN.dll`。以下是一个完整的 Python 程序示例，展示如何初始化设备、发送和接收 CAN 报文。 ### 初始化设备 首先，需要加载动态链接库，并调用初始化函数。以下代码使用 `ctypes` 来加载 DLL 并设置函数参数： ```python import os import time from ctypes import * # 加载 DLL root = os.path.dirname(os.path.realpath(__file__)) dll_path = os.path.join(root, "lib\\ControlCAN.dll") can_dll = WinDLL(dll_path) # 定义常量 class VCI_BOARD_INFO(Structure): _fields_ = [ ("hw_Version", c_ushort), ("fw_Version", c_ushort), ("dr_Version", c_ushort), ("in_Version", c_ushort), ("irq_Num", c_ushort), ("can_Num", c_byte), ("str_SerialNumber", c_byte * 20), ("str_hw_Type", c_byte * 40), ] class VCI_CAN_OBJ(Structure): _fields_ = [ ("ID", c_uint), ("TimeStamp", c_uint), ("TimeFlag", c_byte), ("SendType", c_byte), ("RemoteFlag", c_byte), ("ExternFlag", c_byte), ("DataLen", c_byte), ("Data", c_byte * 8), ("Reserved", c_byte * 3), ] # 初始化设备 can_dll.VCI_OpenDevice.argtypes = [c_uint, c_uint, c_uint] can_dll.VCI_OpenDevice.restype = c_bool result = can_dll.VCI_OpenDevice(3, 0, 0) # 3 表示 USBCAN-Ⅱ+ if not result: raise Exception("Failed to open device") ``` ### 配置 CAN 通道 接下来，配置 CAN 通道的波特率并启动： ```python # 设置波特率并启动 CAN 通道 can_dll.VCI_InitCAN.argtypes = [c_uint, c_uint, c_uint, POINTER(c_int)] can_dll.VCI_InitCAN.restype = c_bool # 波特率设置为 500Kbps init_config = (c_int * 10)(0x001C, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000) result = can_dll.VCI_InitCAN(3, 0, 0, init_config) if not result: raise Exception("Failed to initialize CAN channel") ``` ### 发送 CAN 报文 发送 CAN 报文时，需要构造 `VCI_CAN_OBJ` 结构体并调用发送函数： ```python # 发送 CAN 报文 can_dll.VCI_Transmit.argtypes = [c_uint, c_uint, c_uint, POINTER(VCI_CAN_OBJ), c_uint] can_dll.VCI_Transmit.restype = c_uint # 构造 CAN 报文 can_msg = VCI_CAN_OBJ() can_msg.ID = 0x123 # CAN ID can_msg.DataLen = 8 for i in range(8): can_msg.Data[i] = i # 数据域 can_msg.RemoteFlag = 0 # 数据帧 can_msg.ExternFlag = 0 # 标准帧 result = can_dll.VCI_Transmit(3, 0, 0, byref(can_msg), 1) if result != 1: print("Failed to send message") ``` ### 接收 CAN 报文 接收 CAN 报文时，需要循环调用接收函数并解析返回的数据： ```python # 接收 CAN 报文 can_dll.VCI_Receive.argtypes = [c_uint, c_uint, c_uint, POINTER(VCI_CAN_OBJ), c_uint, c_int] can_dll.VCI_Receive.restype = c_int while True: rx_msg = (VCI_CAN_OBJ * 1)() count = can_dll.VCI_Receive(3, 0, 0, rx_msg, 1, 1000) # 超时 1000ms if count > 0: print(f"Received message with ID {hex(rx_msg[0].ID)}") print("Data:", [hex(rx_msg[0].Data[i]) for i in range(rx_msg[0].DataLen)]) time.sleep(0.1) ``` ### 完整示例代码 ```python import os import time from ctypes import * # 加载 DLL root = os.path.dirname(os.path.realpath(__file__)) dll_path = os.path.join(root, "lib\\ControlCAN.dll") can_dll = WinDLL(dll_path) # 定义结构体 class VCI_BOARD_INFO(Structure): _fields_ = [ ("hw_Version", c_ushort), ("fw_Version", c_ushort), ("dr_Version", c_ushort), ("in_Version", c_ushort), ("irq_Num", c_ushort), ("can_Num", c_byte), ("str_SerialNumber", c_byte * 20), ("str_hw_Type", c_byte * 40), ] class VCI_CAN_OBJ(Structure): _fields_ = [ ("ID", c_uint), ("TimeStamp", c_uint), ("TimeFlag", c_byte), ("SendType", c_byte), ("RemoteFlag", c_byte), ("ExternFlag", c_byte), ("DataLen", c_byte), ("Data", c_byte * 8), ("Reserved", c_byte * 3), ] # 打开设备 result = can_dll.VCI_OpenDevice(3, 0, 0) if not result: raise Exception("Failed to open device") # 初始化 CAN 通道 init_config = (c_int * 10)(0x001C, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000) result = can_dll.VCI_InitCAN(3, 0, 0, init_config) if not result: raise Exception("Failed to initialize CAN channel") # 启动 CAN 通道 can_dll.VCI_StartCAN.argtypes = [c_uint, c_uint, c_uint] can_dll.VCI_StartCAN(3, 0, 0) # 发送 CAN 报文 can_msg = VCI_CAN_OBJ() can_msg.ID = 0x123 can_msg.DataLen = 8 for i in range(8): can_msg.Data[i] = i can_msg.RemoteFlag = 0 can_msg.ExternFlag = 0 result = can_dll.VCI_Transmit(3, 0, 0, byref(can_msg), 1) if result != 1: print("Failed to send message") # 接收 CAN 报文 while True: rx_msg = (VCI_CAN_OBJ * 1)() count = can_dll.VCI_Receive(3, 0, 0, rx_msg, 1, 1000) if count > 0: print(f"Received message with ID {hex(rx_msg[0].ID)}") print("Data:", [hex(rx_msg[0].Data[i]) for i in range(rx_msg[0].DataLen)]) time.sleep(0.1) ``` 该程序实现了 ZLG USBCAN-Ⅱ+ 设备的基本 CAN 通信功能，包括设备初始化、报文发送和接收。可以根据具体需求进一步扩展功能，例如多通道支持、过滤器设置等。