Right-click on the PABX3 icon, choose SHOW.
Select OPTIONS->FILE PATHS -> PABX DLL, select your dll file
from "C:\Program Files\Datatex\pabx3\profiles\lib".
Click on "Save".
Select OPTIONS -> GENERAL, enter your PABX details under
"Description" and "Comments".
Close PABX3.
Navigate to "C:\Program Files\Datatex\pabx3\".
Copy the "pabx.prf" file to "C:\Program Files\Datatex\pabx3\profiles\".
Rename the file to the name of your PABX, example "Panasonic308.prf".