An arpeggiator is basically a step sequencer that plays each note of a chord individually in an ascending or descending pattern across one or more octaves.
Pattern- Defines the order in which the notes of the chord are played. The modes are as follows:
Off- Disables the arpeggiator
Up- Plays the notes in order from lowest to highest.
Down- Plays the notes in order from highest to lowest.
Up/Down- Plays notes from lowest to highest then back to lowest again.
Random- Plays held notes in random order.
Hold- This isn't a pattern per se, but when engaged, arpeggios continue to run without having to continuously hold down keys. This allows you to play a series of chords without the arpeggiator stopping as keys are released. Be aware that it will not stop until you disengage the button again. Mapping this to a sustain pedal or button on a MIDI controller can be useful for conveniently toggling arpeggio playback on and off.
Frequency- Sets the pattern speed playback speed. The LED flashes to indicate the current speed.
Sync- Engaging the Sync button locks arpeggio timing to master tempo. When engaged, the Frequency knob snaps to note values ranging from 1/64th note triplet to 8 beats. Sync mode locks to the tempo in the top toolbar when using the Elka-X standalone version or the current project tempo when the plug-in version is used in a DAW.
Range- Selects how many octaves the pattern will play before repeating.