Thanks for the suggestions guys.

Dave, your suggestions sounds simple enough for me to understand. I guess I could have a variable that is updated every time the program goes around the main loop, then when it reaches a certain value display one set of data for the 1st probe, then when reaches another it displays the second set etc... I'll have a look at implementing that. I guess that provided the program doesn't loop more than 65535 times in 8 seconds then I will be able to use a word variable and each update would be visible for 2 seconds