Code Gui read value in opc data access explorer

my code is below but i can not read data from opc to capture image, please help me!!thank you very much!! It show error

Undefined operator '==' for input arguments of type 'struct'.

Error in camera_camera_OutputFcn (line 101)
if r == 1

Error in gui_mainfcn (line 264)
      feval(gui_State.gui_OutputFcn, gui_hFigure, [], gui_Handles);

Error in camera (line 42)
  gui_mainfcn(gui_State, varargin{:});

function varargout = camera_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;
vid = videoinput('winvideo',1, 'MJPG_1280x720');

% only capture one frame per trigger, we are not recording a video
vid.FramesPerTrigger = 1;
% output would image in RGB color space
vid.ReturnedColorspace = 'rgb';
% tell matlab to start the webcam on user request, not automatically
triggerconfig(vid, 'manual');
% we need this to know the image height and width
vidRes = get(vid, 'VideoResolution');
% image width
imWidth = vidRes(1);
% image height
imHeight = vidRes(2);
% number of bands of our image (should be 3 because it's RGB)
nBands = get(vid, 'NumberOfBands');
% create an empty image container and show it on axPreview
hImage = image(zeros(imHeight, imWidth, nBands), 'parent', handles.axes1);
% begin the webcam preview
preview(vid, hImage);
handles.vid=vid;

da = opcda('localhost', 'KEPware.KEPServerEx.V4');
connect(da);
grp = addgroup(da);
itm1 = additem(grp, 'Channel1.Device1.Group1.capture');
r = read(itm1);
if r == 1
    axes(handles.axes2)
if ~isfield(handles, 'vid')
    warndlg('Please do the oncamera first!');
    return;
end
vid=handles.vid;
pause(3);
data=getsnapshot(vid);
imshow(data);
savename = strcat('Desktop' ,'hinh', '.jpg'); 
imwrite(data,savename);
axes(handles.axes3);
RGB = imread('Desktophinh.jpg');
imshow(RGB);
I = rgb2gray(RGB);
threshold = graythresh(I);
bw = im2bw(I,threshold);
imshow(bw)
bw = bwareaopen(bw,100);
se = strel('disk',2);
bw = imclose(bw,se);
imshow(bw)
[B,L] = bwboundaries(bw,'noholes');
imshow(label2rgb(L, @jet, [.5 .5 .5]))
hold on
for k = 1:length(B)
  boundary = B{k};
  plot(boundary(:,2), boundary(:,1), 'w', 'LineWidth', 2)
end
stats = regionprops(L,'Area','Centroid');
threshold = 0.94;
stats = regionprops(L,'Area','Centroid');

threshold = 0.80;

% loop over the boundaries
for k = 1:length(B)

    % obtain (X,Y) boundary coordinates corresponding to label 'k'
    boundary = B{k};

    % compute a simple estimate of the object's perimeter
    delta_sq = diff(boundary).^2;    
    perimeter = sum(sqrt(sum(delta_sq,2)));

    % obtain the area calculation corresponding to label 'k'
    area = stats(k).Area;

    % compute the roundness metric
    metric = 4*pi*area/perimeter^2;

    % display the results
    metric_string = sprintf('%2.2f',metric);

    % mark objects above the threshold with a black circle
    if metric > threshold
      centroid = stats(k).Centroid;
      plot(centroid(1),centroid(2),'ko');
      text(centroid(1),centroid(2),'hinh tron');
    end
    if metric < threshold
      centroid = stats(k).Centroid;
      plot(centroid(1),centroid(2),'ko');
      text(centroid(1),centroid(2),'khong la hinh tron');
    end

    text(boundary(1,2)-35,boundary(1,1)+13,metric_string,'Color','y',...
         'FontSize',14,'FontWeight','bold');
  end
  end

Answer 1

[Walter Roberson]

It is clear in the documentation that read() is going to return a structure. http://www.mathworks.com/help/opc/ug/read.html

You might want to access the Value field, r.Value

[Luong Tu]

can you teamviewer to help me Walter Roberson

[Walter Roberson]

Sorry, I do not do interactive work as a volunteer. No SMS, no Facebook Messenger, no Skype, no teamviewer, no Snapchat, no Google Hangouts, no phone calls.

[Luong Tu]

I have a code to capture image, but one time, how to capture image one time I write value 1 to opc data access Explorer, thank you very much my code is function varargout = webcam_OutputFcn(hObject, eventdata, handles) % varargout cell array for returning output args (see VARARGOUT); % hObject handle to figure % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure varargout{1} = handles.output; vid = videoinput('winvideo',1, 'MJPG_1280x720');

% only capture one frame per trigger, we are not recording a video vid.FramesPerTrigger = 1; % output would image in RGB color space vid.ReturnedColorspace = 'rgb'; % tell matlab to start the webcam on user request, not automatically triggerconfig(vid, 'manual'); % we need this to know the image height and width vidRes = get(vid, 'VideoResolution'); % image width imWidth = vidRes(1); % image height imHeight = vidRes(2); % number of bands of our image (should be 3 because it's RGB) nBands = get(vid, 'NumberOfBands'); % create an empty image container and show it on axPreview hImage = image(zeros(imHeight, imWidth, nBands), 'parent', handles.axes1); % begin the webcam preview preview(vid, hImage); handles.vid=vid; guidata(hObject, handles); da = opcda('localhost', 'KEPware.KEPServerEx.V4'); connect(da); grp = addgroup(da); grp.UpdateRate = 40; itm1 = additem(grp, 'Channel1.Device1.Group1.capture'); data = read(grp); opcdata= data.Value; if (opcdata==1) opcdata=0; disconnect(da); delete(da); axes(handles.axes2); vid=handles.vid; pause(3); data=getsnapshot(vid); imshow(data); savename = strcat('Desktop' ,'hinh', '.jpg'); imwrite(data,savename); end