Solution:

- The "Date Separator" is "/". User can adjust the "Date Separator" under "Regional Settings" of "Control Panel". - The "Log Period" within the "setup" function of LOGpen program. If the "Log Period" set to "0", it's no doubt to get the message "Floating point division by zero". Basically the "sampling frequency" is from 1 second to 18.2 hours. Please setting the proper "sample frequency" time to this field.