Assuming ApdSLController1 and 2 are components on your form, then the place I would assume the error is coming from is that you added a methods to your form, but didn't make that method a part of your form's declaration. i.e.
Originally Posted by jde08
Form1 = class(TForm)
procedure newprocedure; //make sure you declare the method in your form's type declaration
procedure TForm1.NewProcedure;//without "TForm1." will give Undeclared identifier error.
ApdSLController1.Monitoring := True;
ApdSLController2.Monitoring := True;