Note If exception or error occurred during the procedure (Page 6 / 11) User Manual of MVC SDK Demo (LabVIEW)

User Manual of Machine Vision Camera SDK Demo (LabVIEW)

Note: If exception or error occurred during the procedure, the prompt dialog will pop up.

2.3 Programming Guideline

2.3.1 Introduction of LabVIEW VI

To call the SDK of C API in the LabVIEW system conveniently, sub VI files are encapsulated into the LabVIEW

system. There are total 20 sub VI files in the MvCameraLib.lvlib: EnumDevices.vi, CreateHandle.vi,

DestroyHandle.vi, OpenDevice.vi, CloseDevice.vi, StartGrabbing.vi and StopGrabbing.vi are used for camera

operations, SetValue.vi and GetValue.vi are used to set and get camera parameters, SaveImage.vi is used to

save pictures. This VI files are the secondary encapsulation of SDK of C API, so they contain serval DLLs in the

SDK of C API.

Here we take EnumDevices.vi as an example. The input parameters of this API are nLayerType and error input.

nLayerType is a 32-bit integer, and it is used to input the enumerated device types, the value 1 represents

camera with GigE port, while the value 4 represents camera with U3V port. The output parameters contain

function return, DeviceNum, pstGigEDevArray, pstU3VDevArray, and error output. Function return is the

returned value of called API, return 0 for success, and return negative number (corresponds to error code) for

failure. DeviceNum is the number of enumerated cameras. pstGigEDevArray is the cluster array of GigE

camera information, while pstU3VDevArray is the cluster array of USB3 vision camera information. See the

definition of device information structure below:

typedef struct _MV_CC_DEVICE_INFO_

{

// common info

unsigned short

nMajorVer;

unsigned short

nMinorVer;

unsigned int

nMacAddrHigh; // MAC address

unsigned int

nMacAddrLow;

unsigned int

nTLayerType; // Device transport layer protocol type, e.g.,

MV_GIGE_DEVICE