Home / ABB / ABB Drives / ABB AC Drives / ABB ACS880 Drive / ABB ACS880 Drive Options Code / ABB ACS880 Drive +Q972, +L521 Optional Code, FSO-21+FSE-31 (Safety functions module FSO-21 and encoder FSE-31)ABB ACS880 Drive +Q972, +L521 Optional Code, FSO-21+FSE-31 (Safety functions module FSO-21 and encoder FSE-31)