It’s my understanding that the OSPI supports a maximum of 56 stations, the main unit supports 8 stations and a maximum of 3 expansion units each supporting 16 stations for a total of 56 stations. Thus, sbits should look like this “sbits”:[0,0,0,0,0,0,0] instead of looking like this “sbits”:[0,0,0,0,0,0]. There are 7 positions in the first sbits to account for all 56 stations whereas the second sbits only accounts for 48 stations. My gut feeling is that sbits should account for all 56 stations.

I completely understand your explanation and it makes sense. But the return value of sbits still has me confounded.