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Delta_T is the number of packets missed since the last time your PBasic program successfully got data from the Master CPU (which gets its data from the Operator Interface).
It was an attempt by FIRST to allow a little bit of "real time" control by giving the robot programs knowledge of how much time has passed since they maded it through the loop successfully.
The data is better than nothing, but it leaves a lot to be desired as a real time clock.
From time to time, I have used Delta_T or its twin packet_num to implement a counter that serves as a clock. It has some uses but it is very limited because the best resolution that you get is 25msec which is not all that great at times.
Hope this helps.
Joe J.
P.S. Typical Delta_T's should be 0, 1 or 2. The most I would recommend you live with is 4 -- absolutely MAX. Note that at 6 some rather drastic things start happening -- namely, the Master CPU thinks you are lost in a loop somewhere and turns off all your outputs -- this is not a good thing, believe me. If you consistently run at 5 for Delta_T you are only one radio interference problem from not working at all -- to my mind a very dangerous thing to risk. JJ
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