Receivers with PPS require PULL UP (Pull-Hi) 10K
This circuit exists inside of the receiver with a logic level of 0,7V at the PPS output (PPS_OUT). Use a "Pull Up" 10K Ohm resistor with the desired logic level (V_System) for the ajustment (red circle).
PPS (Puls Per Second)
Periode 1Hz, Signal 100ms