Can Xbee end device transmit a pulse/any data to coordinator?

Can Xbee end device transmit a pulse/any data to coordinator?

Sure any node within the network can send UART data to any other node within the network. In fact all routers and end devices send their UART data to the Coordinator by default.

my problem is I need to send a pulse to my coordinator, so of course my coordinator must be in API right, so which mode is more suitable for router and end device?

And how coordinator can detect the pulse changes? is there any references about the hex code for the frame?