actually this is NOT TO JUST HAVE A number the p stands for pan and r and small L stands for right and left pan movement , when the comes it makes sure to drive that condition only that will put analogWrite PWM values to turn it right but on a specific PWM speed ,all these values are received over XBee pro and it seems to work well with this sketch TOTALLY FINE untill i got those Speed PWM functioning in there, Still the TILT of the BASCOR PAN TILT works very very fine so i DO not think the resetting of started and ended is needed(if definitely needed please tell some detailed viewpoint)
There is still no need to convert your null-terminated string into a String. It's just wasting memory.
Resetting started and ended is necessary, because, as John said, process() will continue to be called whether a complete string has been received or not.