# Serial Port cannot get data sometimes during start up

**URL:** <https://discourse.nodered.org/t/serial-port-cannot-get-data-sometimes-during-start-up/16844>\
**Category:** General\
**Created:** [18 October 2019 07:42 UTC](https://discourse.nodered.org/t/serial-port-cannot-get-data-sometimes-during-start-up/16844 "2019-10-18T07:42:22Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![AK51](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ak51/32/8438_2.png) [@AK51](https://discourse.nodered.org/u/AK51)\
**Post date:** [18 October 2019 07:42 UTC](https://discourse.nodered.org/t/serial-port-cannot-get-data-sometimes-during-start-up/16844/1 "2019-10-18T07:42:23Z")

</div>

I have 3 arduino running with USB at 115200 bps. When I start my computer, I see the three serial nodes are labelled connected. But sometimes, I don't see any data from one or two port during startup. I need to unplug and plug the USB several times to restart the data transfer.  
My data is like this 111,222,333,444,555,666,777,/n And the data packet rate is 1Hz only.

And I also think may be the arduino does not have enough power, so I add external 5V to one of the board. No lucky.

Is there any setting I can try in the serial port node?

My Arduino code is simple  
void setup() {  
Serial.begin(115200);  
}  
void loop() {  
...delay  
Serial.println(xxx);  
}

I saw in a website ([https://arduino.stackexchange.com/questions/439/why-does-starting-the-serial-monitor-restart-the-sketch](https://arduino.stackexchange.com/questions/439/why-does-starting-the-serial-monitor-restart-the-sketch)) says  
" The Arduino uses the [RTS (Request To Send)](http://en.wikipedia.org/wiki/RS-232_RTS/CTS#RTS.2FCTS_handshaking) (and I think [DTR (Data Terminal Ready)](http://en.wikipedia.org/wiki/Data_Terminal_Ready)) signals to auto-reset."

Can I trigger the RTS in the serial port node?

Thanks