While running the .m file, I got error like this. What may be the reason??

Error using ==> @(hObject,eventdata)untitled('dutyedit_CreateFcn',hObject,eventdata,guidata(hObject))
'dutyedit_CreateFcn' is an invalid option

??? Error using ==> struct2handle
Error while evaluating uicontrol CreateFcn

??? Error using ==> open at 29
Mode for channel "duty_ichan" must be a character:
'r'/'R' for read, and 'w'/'W' for write.

Error in ==> mask>untitled_OpeningFcn at 68
open(cc.rtdx,'duty_ichan','U');% open RTDX channel for duty_ichan %

Error in ==> gui_mainfcn at 221
    feval(gui_State.gui_OpeningFcn, gui_hFigure, [], guidata(gui_hFigure), varargin{:});

Error in ==> mask at 42
    gui_mainfcn(gui_State, varargin{:});

[Geoff Hayes]

Allya - what is the line of code

 open(cc.rtdx,'duty_ichan','U');

trying to do? Is duty_ichan a variable of some kind that has been assigned a value of 'r' or 'w'? Please provide some context.