If you're looking for RTU, you can do 'display capacity'. On page 9 it will show you station RTU: total, used, & spare.
If you want a physical port count you can do the following:
Using ASA select 'Reports' then type 'list config all' and 'export screen capture to file'.
Use Microsoft Excel to open the saved file. You will need to select 'all' as the file type to
see the save config file.
In spare columns you can enter the board capacity, i.e. TN2224=24, etc., and used ports. Then
let Excel add them up for you.
Beginning in CM 3.x RTU only applies to stations, not trunks.
Kevin