fSTTimeSince aa+ [D>=16]
Calculates the difference between the current System Time and the value stored in 3 bytes of RAM at address aa. The result is the elapsed time since the System Time was captured to aa, and is returned as a floating point number in W. This will be an integer value in the range 0 to 16,777,215 times 10mS. This instruction is not confined to use in a MultiTrack task. It is based on the assumption that there was a prior STStart instruction.
From dialect 20 some controllers allow you to program the 10mS basic "tick" interval over the range 1mS to 255mS via a setting in the CPU device. See the CPU device documentation for your controller.
The address argument aa will be jndexed when executed inside a MultiTrack task and will be indexed if the instruction is preceded by the IasJ: precode.
Dialect exclusions: Not available in dialects before 16.