what is tp function


The old style 33/35 exit device trims will not function with the newer "33A/35A" exit devices and newer style trims will not work with the older 33/35 exit devices.
TP, Classroom Function (BHMA Exit Function)
No, the E option (electric locking/unlocking of the mortise lock body) requires a functional L, TP, or K trim, but the cylinder would operate in a night latch function as desired.   Order E9975L/TP...
TP-2, Double Cylinder Option (BHMA Exit Function)
Recommend to order a new 990NL-R/V or M trim to change from TP/Classroom function to NL/Storeroom function. You will also need to reinstall the NL drive screw back into into the mast...
TP-NL, Thumbpiece Night Latch Function (BHMA Exit Function)