Using XB9X-DM, XBee SX, firmware 9007 setup as a Router in API 1 mode. Router XBee controlled by MCU acting as a client that periodically polls three (Non-routing) end devices via TX Request frames 0x10. Works great - as long as all end devices are powered up.
With two of the devices offline and polling process marching on, the router/client XBee randomly sends a frame type 0xFE to the MCU. 0xFE frame has one data byte = 0x04.
1. What is frame type 0xFE? Not in XBee®/XBee-PRO SX v90001477 user manual.
2. How to recover?
Many bad things happen, random Legacy TX Status frames, ND does not work, XCTU cannot communicate remotely...