Dear all, I know that this topic rises several times in the past, but I did not found helpful suggestion in that posts. Can you please help me to get the correct cluster for a typedef struct for a call library function node. I want to send and receive CAN frames to and from a gas sensor. The CAN converter is USB connected and only programmable by a DLL. Please find attached the typedef struct description from the DLL API manual and a VI with call library function to get the board info. typedef struct _VCI_BOARD_INFO {USHORT hw_Version;USHORT fw_Version;USHORT dr_Version;USHORT in_Version;USHORT irq_Num;BYTE can_Num;CHAR str_Serial_Num[20];CHAR str_hw_Type[40];USHORT Reserved[4];} VCI_BOARD_INFO, *PVCI_BOARD_INFO; hw_VersionHardware version number, hexadecimal notation. E.g. 0x0100 represents V1.00.fw_VersionHardware version number, hexadecimal notation. E.g. 0x0100 represents V1.00. dr_VersionDriver version number, hexadecimal notation. E.g. 0x0100 represents V1.00.in_VersionInterface library version number, hexadecimal notation. E.g. 0x0100 represents V1.00.irq_NumSystem reserved.can_NumRepresents the total number of CAN channel.str_Serial_NumThis board card's serial number.str_hw_TypeHardware type, such as “USBCAN V1.00” (Note: Includes string terminator ’\0’).ReservedSystem reserved. --- DWORD __stdcall VCI_ReadBoardInfo(DWORD DevType,DWORD DevIndex,PVCI_BOARD_INFO pInfo);Parameters:DevTypeDevice type. See: Adapter device type definition.DevIndexDevice Index, for example, when there is only one USB-CAN adapter, the index number is 0, when there are multiple USB-CAN adapters, the index numbers in an ascending order starting from 0.pInfoVCI_BOARD_INFO is used to store device information structure pointer.Returns:Return value = 1, which means that the operation is successful; = 0 indicates that the operation failed; = -1 indicates that the device does not exist.

It’s even simpler. You only need to create the cluster itself for VCI_CAN_OBJ correctly. Then initialize an array of it. Configure the parameter as Adapt to Type and Pass as: Array Data Pointer. Make sure to pass for the next parameter a value that is NOT greater than the number of array elements you initialized.

Array to cluster can only build clusters of up to 256 elements. If I'm interpreting that function call right you can use a smaller array if you match the second-to-last parameter of the function call. You can create a cluster for VCI_CAN_OBJ, flatten it to string, get its length, initialize a byte array with n*length and pass that array by pointer to the dll. Then unflatten the data. Something like this.

You cannot use nested arrays in the cluster. LabVIEW will pass their handles in the cluster to which is not what the library expects. It wants fixed sized arrays. Either convert your arrays to clusters using array to cluster and the appropriate size. Or pass a byte array of at least sizeof(_VCI_BOARD_INFO) elements by pointer. You can take it apart element by element in LabVIEW after the call. The data type for can_Num, str_Serial_Num and str_hw_Type should be u8.