Just to confirm, there is no concept of transmitter and reciever is there? I have two of these sets and I am struggling to get them to speak to eachother and now I am wondering if I am wrong?! Two...

Model : Hardware Version : Firmware Version : ISP : I have tried two sets as I thought the ones I had were broken. I cannot get two of these kits (4 units) working together. There is always one or...