Alesis ALESIS M20 owner manual Chase Reference, SMPTE, Sync and Offset, 11-3

Chapter 11, SMPTE, Sync and Offset

For example, Int Gen always generates time code when the Internal Generator TC Start Ref parameter is set to User Set, Free Run, and the TC Input button is lit. Setting this parameter to ABS Time generates time code only if there is a valid, ADAT-formatted tape in the transport. Setting this parameter to TC Track generates time code only if there is valid time code recorded on the TC track of the tape.

With the Time Code track in Input mode, the time code start point and internal generator functions vary, as shown below.

TC	Int Gen	Intern	Internal Gen will…	How Time Code Starts
Source	Start Ref	Gen
Mode		status
External	N/A	Disabled	N/A	Input time code passes through
				to the output
Internal	ABS	Enabled	Run immediately (in	Time code starts from the ABS
	Time		Free Run mode) or when	time + internal generator ABS
			tape is moving (in	offset
			Play/Rec mode)
Internal	User Set	Enabled	Run immediately (in	Time code starts from the
			Free Run mode) or when	specified time
			tape is moving (in
			Play/Rec mode)
Internal	TC track	Enabled	Run immediately (in	Internal generator time code
			Free Run mode) or when	starts from the TC track.
			tape is moving (in
			Play/Rec mode)

Caution: If the TC track is put into record when the internal generator is disabled and the TC track is in Input mode, the TC track will record no time code and will erase any previous TC track time code.

11.4CHASE REFERENCE

Chase Reference chooses between two chase (synchronization) reference options. The tape time code playback mode automatically follows the incoming time code frame rate.

∙With ABS Time mode, the M20 will chase incoming SMPTE based on its absolute time reference (the standard ADAT-format time code).

∙With Tape TC mode, the time code track recorded on tape provides the reference for locking to incoming SMPTE. If there is no time code on tape, the tape will not chase incoming SMPTE.

Note: In both cases, when synchronizing to optical or word clocks, the time code must be synchronous to the sample rate (this will always be the case if synchronizing to absolute time; if synchronizing to tape time code, the TC track must be synchronous to the clock). For the M20 to lock, you must also make sure that the incoming time code is synchronous to the incoming word clock.

ALESIS M20 REFERENCE MANUAL 1.06 11-3