Remote gate light

I will give an overview of the project first.
We have a gate to our warehouses. I would like to turn a light or bell on in the 2 warehouse when the gate is opening (to let me know when a customer is on their way in) I would also like to be able to press a button in the warehouse to send a signal to the gate to open.

Basically I would like the activation of a relay in the gate to send a signal to 2 Different XBee’s(1 in each warehosue) to turn on a relay(to turn a light on).

I would also like the press of a button in the warehouse to activate a relay in the 1 xbee in the gate.

I’m new to the xbee family so I’m just looking for a little guidance

I’m looking at a distance of about 300 ft between each xbee so was going to go with the XBee-PRO 802.15.4 through-hole module w/ RPSMA connector and mount an external antenna to the steel warehouse walls

I am looking for a guidance on the configuration of each XBee. I am thinking of a Coordinator and multipoint setup. Do you recommend API or AT mode?

why are you not just using the DIO line passing function of the XBee 802.15.4? http://knowledge.digi.com/articles/Knowledge_Base_Article/XBee-802-15-4-Digital-Input-Output-Line-Passing/?q=DIO+line+passing&l=en_US&fs=Search&pn=1

I am doing digital IO line passing. I have posted another question to make it more simple. Here it is. what am I missing?

Looking for programming help. I have 3 XBee pro S2C (lets call them G, H1, and H2 just for labeling) modules. I am looking for 1 input on “G” to be an output on the other 2 “H1, H2”. Also I would like 1 input on the 2 to be and output on the 1. Here is what I am using.

I am using the sparkfun USB Explorer Board for each and the Beefcake Relay to be what needs to be switched on each.

XBEE “G” I have a button on PIN 11 (DI4) to ground (Input). I also have the Relay control on PIN 20 (DO 0).
Programming I have them on 802.15.4 TH Pro. Everything is default except. D0 is set to DO Low. D4 is set to DI. IC set to 10 (D4 Change detect).

XBEE “H1 and H2” I have wired the same. Button on PIN 20 (DI0) and Relay on PIN 11 (DO4). Programming I have them on 802.15.4 TH Pro. Everything is default except. D0 is set to DI. D4 is set to DO Low. IC set to 1 (D0 Change detect).

I have set G as coordinator and the other 2 as end points. I have set them all to end points. I Have even tried to just get G to connect to H1 by setting the destination on each and eliminating the H2 just to start. when I press the button I am getting an RSSI light on the receiving xbee. It is not activating the Relay though.

I have also set the DO to High and that manually turns the Relay on but it will not change the state.

Anyone have any advice for my stuck project and where I have messed up getting the output to change state?