I have a created a spreadsheet that uses a DDE link to show values from plant
equipment. The information is displayed on four cells in sheet1. I have put
together a macro that copys the information from the four cells in sheet1
and pastes the information on sheet 2. This routine runs every second and
moves to the next cell. . It saves the information every seven hours and
starts over. In other words I know what the equipment was doing every second
during a 7 hour shift. The program seems to work fine when I test it in the
office, without the link and without letting it run 7 hours. When I leave it
running on the machine the program crashes, I have not seen the error that
comes up.

Will a DDE link cause any type of error that can stop the program from
running?
Is there a way to program around DDE errors?

This is the only program running on this computer can windows cause it to
crash in any way?