In looking at a pdf of the installation manual, I see that the TPU-15A has "night bell" built in via dry contacts. So you would need another piece of hardware, a 90VAC relay (Wheelock makes one, I could find a part number on it next week). You would connect the coil of this relay to a Partner station port, and the contacts of the relay to the dry contact night ring input of the Bogen. Program the Partner station to no ring on incoming, and put it in the night service group, and of course add a night service button to Ext. 10.