Freewheel mode
Freewheel is a resilience feature for chase mode. When the incoming LTC signal drops β due to a cable problem, a source that pauses, or a brief interference dropout β freewheel allows LTCast to continue running at the last detected rate rather than stopping all outputs immediately.
Enabling freewheel
Open Settings β Timecode In β Chase tab and toggle Keep running when LTC stops on. Freewheel only activates when chase mode is also enabled; it has no effect in normal playback mode.
Behavior without freewheel
When LTC drops and freewheel is off, LTCast immediately stops advancing the timecode and shows LTC SIGNAL LOST in the status bar. All outputs β MTC, Art-Net, OSC β stop sending updates. Devices downstream that require a continuous timecode stream (lighting consoles, media servers) will stop or go into a "signal lost" state of their own.
Behavior with freewheel
When LTC drops and freewheel is on, LTCast transitions to Freewheeling status. It continues advancing the internal timecode counter at the same frame rate it detected before the dropout. All outputs continue without interruption β MTC keeps sending quarter-frame messages, Art-Net keeps sending OpTimeCode packets, and OSC keeps sending position messages. Downstream devices remain in sync as long as freewheel continues.
When the LTC signal returns, LTCast detects the valid frames and snaps back to the incoming timecode position immediately. There may be a brief jump if the signal returns at a significantly different position than the freewheel estimate.
Run past end of song
By default, the freewheel clock stops when it reaches the end of the currently active song's duration. Enable Run past end of song to allow the freewheel counter to continue counting past the song boundary. Use this when the LTC source may run longer than the audio file loaded in LTCast, or when you are using LTCast purely as a protocol bridge without local audio files.
Freewheel is most valuable for brief, unexpected dropouts β cable bumps, connector loosening, brief interference. For extended outages (more than a few seconds), the freewheel clock will drift from the true timecode due to clock differences between machines. In this case, re-locking to the source when it returns is the correct behavior; the snap-back on re-lock is expected.
Freewheel uses the computer's internal system clock as the oscillator once LTC is lost. System clocks are accurate to a few milliseconds per minute but are not SMPTE-grade oscillators. For shows where sub-frame accuracy is critical after a dropout, physically securing cables and preventing dropouts in the first place is preferable to relying on freewheel.