I am using XBee and XBee Pro modules (with 10E8 firmware) in the following constellation:
The first module is programmed to be a Coordinator using the default Channel and Pan ID. It is set to not use the Sleep Mode and its Cyclic Sleep Period (SP) is set to 100. The Coordinator Association (A2) is set to 6.
The second module is programmed to be an End-Device, also using the default Channel and PAN ID. It is set to use Sleep Mode 5 with a Time before Sleep (ST) of 500 and a Cyclic Sleep Period of 100. Additionally it’s End Device Association (A1) is set to 6.
This setup is working perfectly regarding the sleep-mode and power-consumption. The end device associates with the Coordinator, it goes into sleep and powers down.
However when the Coordinator sends data to the End Device, that data is not received at the End Device. It wakes up - but no data is transfered to the End Device. Only data that is transferred while the End Device is in the waking state is actually received. Once the Device falls back into Sleep Mode all transferred data is again lost completely.
It seems that either no data has been cached at the Coordinator or that the End Device does not poll the Coordinator once it wakes up.
Has anyone experienced this problem or has an idea for a solution?
I must confess that I am currently at a loss for further Ideas. I’ve tried combinations of XBee Pro and XBee modules and sending Broadcast and Unicast data - each time with the same result: as long as the End Device doesn’t enter Sleep Mode everything is fine. Once it enters Sleep mode I cant transfer data to it.
Help would be greatly appreciated.
thanks in advance