Anyone familiar with XBEE?

Hi Everyone,

I'm currently working on a project that has xbee as one of its requirements. However, I've never used xbee before and is having some problems. I was wondering if any of you could help me with some of the xbee settings.

So here's how my project is supposed to work:

I'll be using 3 xbee modules(set as transmitters) which are connected to 3 different sensors. Data from this sensor will go through a microcontroller and would then be transmitted using xbee. There'll be one xbee module(receiver) connected to a microcontroller to a pc to monitor the data from the sensors.

Currently, my xbee settings are as follow:

Transmitter A
-ID 3332
-DH 0
-DL 0
-MY 1

Transmitter B
-ID 3332
-DH 0
-DL 0
-MY 2

Transmitter c
-ID 3332
-DH 0
-DL 0
-MY 3

Receiver
-ID 3332
-DH 0
-DL ffff
-MY 0

But the problem I'm currently having with is that the data from the 2 transmitting xbees are "clashing" at the receiver, causing the data to be distorted. Is there a way to set the xbee so that the receiver xbee polls the transmitted data instead of receiving the data at the same time.
(Receiver polls data from Transmitter A->Transmitter B->Transmitter C-> Transmitter A)

Thank you in advance.