The topic of controlling scan timing is discussed in detail in the Scan Times section.
STOP is used to specify the stop time of the scan in UT. If LST is specified, the time is in local sidereal time. Either a STOP time, a DURation, or a DWELL must be given for each scan, although the DURation or DWELL can default to a previous value. If STOP and one of the others are both given then the implied stop times are compared, and if those times differ by more than 10 seconds, a complaint is generated. A simple check of a long schedule made in durations is to include the stop time for the last scan; if the schedule has problems, there will be an error message.