Interfacing a Microcontroller with a RF module

Hi,

I want to send a control command from one pic to the other using rf modules.
This is the setup...

I want pic1 to send a command using rf1, rf1 then transmits
rf2 receives, sends command to pic2
pic2 then sends command to an ultrasonic tx.

pic1 and rf1 are connected by wires, so are pic2 and rf2.

This command would be to activate this usonic tx to send a signal. no more no less.

I figure I could either send for example a few bits like '111', pic 2 would keep checking to see if the command has been received, if yes then it would activate the TX.

Could this work or is there an easier/better way?
I am new to rf modules but know the basics of pics.

The rf modules I want to use are TXM-xxx-LR and RXM-xxx-LR.

Thanks in advance!

Check my PIC tutorials which cover RF modules.