Serial Servo Control using PIC
Firstly, Your code is blocking. That's not the way to wait for serial data. You will have to monitor the RX interrupt flag from the main loop and if set do the ip1=rx_data(); to get the data. In your case, if your wiring of the UART pins are wrong or there is no data from the master MCU, the line while(PIR1.RCIF==0); is an infinite loop. That explains why the rest of your code doesn't work.

Second thing I noticed is that you are giving the servo only one pulse per control signal. Most hobby RC servo motors expect at least 3 such pulses to reliably position the horn.