*The E-X20 is distributed in limited countries/areas.
Yes, it is possible.
When using a half-damper supported pedal Roland DP-10 (sold separately), set the function switch to the "Switch" (switch control) side, then turn on the power.
NOTE: The E-X20 does not support half-pedaling technique.
See also the related Q&A "Does it support half-pedaling?" and "The pedal switch is working in reverse."