Proper sensor controller startup procedure

I'm scanning a keypad button matrix with the sensor controller on the CC1310. I have this working now but am confused about the startup procedure.Is it necessary to call scifStartRtcTicksNow() and scifStartTasksNbl()? My impression was that the first function ran the task periodicly and the second function was to run the task once. Thanks for any clarification.

Here is my code.

scifOsalEnableAuxDomainAccess();

	// Initialize the Sensor Controller
	scifOsalRegisterCtrlReadyCallback(ctrlReadyCallback);
	scifOsalRegisterTaskAlertCallback(taskAlertCallback);

	//start sensor controller for key scan
	SCIF_RESULT_T res = scifInit(&scifDriverSetup);
	scifStartRtcTicksNow(2162);

	//enable interupts
	IntMasterEnable();

	//start rtc
	AONRTCEnable();

	scifStartTasksNbl(BV(SCIF_KEYSCAN_TASK_ID));