Nodemcu startup issue,

I am working on nodemcu unit from amica.I have code running successfully with modbus rtu device

connected . Now i am issue with when power off and power on of nodemcu unit.

when power went off my TX2_nodemcu-> Rx_modbus_RTU RX2_nodemcu-> Tx_modbus_RTU kept

connected as per application. so i expected when power on automatically nodemcu should restart device.

when power on device wont respond at all. if i remove Tx & rx line press reset button device will be

connected then after connecting TX & Rx line device start responding.This should not happen ideal

working condition. Is there any way to avoid it, so it take some boot time and connect automatically.

Is it possbile ato attach external antena to node mcu unit??