How long to wait after reset of XBEE module before communicating with UART?

I’m working on a project with XBEE ZNET 2.5 plug in modules. We have the ability to reset the XBEE (pin 5) with a microcontroller. We have a need to periodically reset the XBEE and then communicate ASAP. The XBEE spec does not define how long XBEE module requires to boot before one can communicate with its UART.

We’ve appears to take up to 30 seconds before it will reliably respond to UART commands.

What is the required powerup time of XBEE unit after reset?

When you say “respond to UART commands”, do you mean respond to an AT command or to send data to another module? If you mean AT commands then it should take less than one second, but if you mean to send data to another module then that is dependent on many factors.