Really thanks for your help, i make some progress:
with firmware XBP24BZ7 in AT mode with correct settings i have 100% good package in test range (20000 package 32bits).
I'm not clear what your preferred interface is, AT or API?
Im not sure about benefits to use AT or API, im new in xbee world sorry:( im learning at this point, i want use this two xbee to comunicate between two arduino uno for an Robot (One for robot chassis and other one for commands). i have third xbee and want to use this connected in PC with usb explorer shield to comunicate to other two arduino by xbee network to send sketch and send comands. With actual configuration i think i can´t add this third Xbee, it´s mandatory use API mode for more of than 2 xbee?
Jack Christensen sorry for my questions, but can you explain the diff between AT and API? and why i use a firmware diferent of original modem of my xbee´s?it is normal operation?