communication between XBee Explorer USB and XBee shield

Hi.

I purchased Arduino uno, XBee shield, two XBee Series 1 models and XBee Explorer USB. I am following this instruction.

https://learn.sparkfun.com/tutorials/xb … 1438701741

I am using Mac Yosemite to test the product and a sample code posted on the link. I was able to compile the sample code (posted on the link) and upload it into the Arduino UNO. But when I test it on the XCTU and Serial Monitor (launched from Arduino IDE), I don’t see any communication data between these two products. I don’t see any error either. I sent a simple text from the Serial Monitor and pressed ‘Send’. I was supposed to see the same text on the XCUT (which is connected to the XBee Explorer USB), but I don’t see any text. I even used other serial monitor CoolTerm Mac, but i don’t see any text either.

On XCTU, I am able to connect to the XBee Explorer USB.

Can anybody tell me how to troubleshoot this and what to check?

Thanks