Normal SPLat inputs are capable of latching an OFF to ON transition. This is handy for such things as reading input button presses. The WaitOnK ii instruction will stall until a transition is registered on input ii. This could be a transition that was captured and stored before the instruction is executed. If there is no such prior transition, the instruction will wait indefinitely for a new transition. In a MultiTrack task this is not a problem.
Executing the WaitOnK instruction clears the latched transition, so a new OFF to ON transition would be required for a second WaitOnK to respond.
Dialect exclusions: Not available in dialects before 9.