In what field? ABET has a variety of different accreditation programs, for different disciplines like engineering, computer science, technology, surveying, industrial hygiene, etc. There are only a handful of ABET-accredited programs, in any field, that are 100% online. They are listed here.
Excelsior has two ABET-accredited technology programs: the BS in nuclear engineering technology and the BS in electrical engineering technology. However, these programs are not considered 100% online, because they require some "physical" lab work. For example, the BSEET requires seven labs, "at least two of which must be physical (non-virtual)". So Excelsior is ABET accredited for those programs, but they don't make ABET's "100% online" list.
I would like to know what they mean by physical vs. virtual. There are virtual labs done on computers and physical labs done in one's home.