at command

Hello everyone.
Foreword my lack of knowledge in programming, I ask for help on a problem.
I have two arduino shield with Xbee S2 (an end device and a coordinator).
I'm trying to get them to communicate with each other and get the value of RSSI using the DB called via AT commands. The problem is that the total is 0 even when the devices are associated.
Both devices are in API mode.
I attach the sketch that I wrote
Thank you in advance for any help.

#include <XBee.h>
#include <string.h>

AtCommandRequest Request AtCommandRequest = ();
AtCommandResponse AtCommandResponse Response = ();
XBee XBee xbee = ();
uint8_t DB [] = {'D', 'B'};

int timeout = 1000;

void setup () {
xbee.begin (9600);
delay (500);
}

void loop () {
nodeCount int = 0;
Request.setCommand (DB);
Serial.print ("Sending command to the XBee");
xbee.send (request);
Serial.println ("");

while (xbee.readPacket (timeout)) {
if (xbee.getResponse (). getApiId () == AT_COMMAND_RESPONSE) {
xbee.getResponse (). getAtCommandResponse (Response);
}
}

Serial.print ("Results");
int i = 0;
while (i <Response.getValueLength ()) {
i ++;
}
Serial.print (Response.getValue (), HEX);
Serial.print ("");

Serial.println ("");
}

After 20 posts, you should know how to post on this Forum. Since you don't, read Nick Gammon's two posts at the top of this Forum on how to properly post source code. You'll get more responses if you follow the guidelines and use code tags when posting source code.

Both devices are in API mode.

But you are sending them AT commands. Why is that?

XBee XBee xbee = ();

Say what?

No Serial.begin() in setup() means that none of your Serial.print() statements are going to work.