My data acquisition plots five y values along a time axis. There are occasions when the number of plots is less than this due to user set-up of the test. The problem that I have is that the XY graph continues to plot all five values with the empty values drawn on the zero line of the y-axis. Whenever I try to disable the visible property of the plots it doesn't seem to recognise them as active plots and delivers an error code saying 'Invalid property...."etc. The plots can be made invisible only if the user choose to acquire 5 sets of data. Can you help?