What's the REAL difference between API and AT modes?

, ,

So Something strange happened. I am experimenting with 3 Xbee S1s in API and AT modes. The two API ones are far away, the AT/transparent mode one is in the middle. Well, the middle one doesn’t seem to be transmitting anything. It is receiving stuff, the RX led is blinking on the explorer I attached, but not the TX led. Also, whatever frame I happen to get on my listening end has the SL of the far, transmitting end.

The mid-point Xbee in transparent mode has MY set to 00.
I expected to get more frames from 00 and less from the far end. Maybe the S1s are not working the way I thought? Has anybody conducted the same experiment (two far endpoints, one transparent midpoint) with different results? Thank you.

There is no response in AT mode for ADC or DIO data on the UART. You must use API mode for that.