Not able to generate the receipt form pos in PDF format .
In Print Profile Print type is not selected as "show printer selection".
Follow the below steps,
1.Administration > Retail Configuration > Print Profile.
2.Select the Printer type(show printer selection from drop down list ) .
3.Select Report id (transaction receipt ) from the list of report id follow screen shot .
4. Then go to Pos and perform transaction after that select the printer option from the given list Follow the below screen shot .