Connectors section at
Specifications tab on this page contains the following:
PEDAL (DAMPER/R, SOFT/L *, SOSTENUTO/C *)
So I'll presume, that those are the pedals required for the answer.
As stated at Piano pedals article on Wikipedia:
Modern pianos usually have three pedals, from left to right, the soft
pedal (or una corda), the sostenuto pedal (mainly found in
American-made grands), and the sustaining pedal (or damper pedal).
To test the damper (or sustain) pedal You should:
- press the damper pedal (obviously)
- play some notes staccato
- the result is all notes that You've played should continue to sound
until You release it
To test the soft pedal:
- press the soft pedal
- play some composition
- you will hear, that it sounds quieter (comparing to playing the same
composition without pressing the soft pedal)
FYI: soft pedal is also called
tre corde means three strings. On a non-digital piano the hammer strikes all the three strings that correspond to some single key that You press. This is the state of the piano when soft pedal is not pressed.
una corda means one string. This is the state of the piano when soft pedal is pressed.
So, basically, this is
tre comparing to
una. This should give You the idea of how much softer (quieter) the composition fragment should sound when You press the soft pedal.
FYI 2: You can find
una corda remarks in urtexts of compositions written by Ludwig van Beethoven.
For example, in
Ludwig van Beethoven, Sonate für Klavier (B-Dur) op. 106, Artaria, 2588 in third movement, Adagio Sostenuto on page 25 at
Beethoven-Haus in Bonn - Digital Archives here.
To test the sostenuto pedal:
- play some chord, for example, C-major and hold it while You press
the sostenuto pedal
- now release the chord (but do not release the pedal)
- now play the C-major scale
- the result is You still hear the C-major chord, but not the C-major
Piano pedals > Sostenuto pedal:
By using this pedal, a pianist can sustain selected notes, while other
notes remain unaffected.