# Multiple (5) serial inputs to raspi using usb ports

**URL:** <https://discourse.nodered.org/t/multiple-5-serial-inputs-to-raspi-using-usb-ports/30659>\
**Category:** General\
**Created:** [24 July 2020 16:14 UTC](https://discourse.nodered.org/t/multiple-5-serial-inputs-to-raspi-using-usb-ports/30659 "2020-07-24T16:14:38Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![panmanjon](https://avatars.discourse-cdn.com/v4/letter/p/dfb087/32.png) [@panmanjon](https://discourse.nodered.org/u/panmanjon)\
**Post date:** [24 July 2020 16:14 UTC](https://discourse.nodered.org/t/multiple-5-serial-inputs-to-raspi-using-usb-ports/30659/1 "2020-07-24T16:14:38Z")

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OK newbie here - I am using 5 usb ports on the raspberry pi to read 5 serial inputs - it all works fine but at the moment I have to carefully plug in each usb port in a specific order so that the port matches up to the specific system associated to the serial node. Each of my inputs has a different baud rate so the order of plugging in is critical to get things right.

My question is that is there a way for me to plug in my usb ports in a random order, not critical but more worrying is that if a hardware system input fails the raspi will re allocate the /dev/ttyUSB and than the node-red flow will not read in the other 4 serial inputs which is not so good. The 5 systems are as follows: BMV 712 meter, MQQT solar input battery charger, adafruit GPS and 2 custom made chargers

Thanks

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**Author:** ![JGKK](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/jgkk/32/18515_2.png) [@JGKK](https://discourse.nodered.org/u/JGKK)\
**Post date:** [24 July 2020 16:24 UTC](https://discourse.nodered.org/t/multiple-5-serial-inputs-to-raspi-using-usb-ports/30659/2 "2020-07-24T16:24:49Z")

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You could work with giving each device a unique symlink with udev rules and address them with this symlink from nodered. There is is many tutorials on this online, for example this one here:

[http://hintshop.ludvig.co.nz/show/persistent-names-usb-serial-devices/](http://hintshop.ludvig.co.nz/show/persistent-names-usb-serial-devices/)

Johannes

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [7 August 2020 16:24 UTC](https://discourse.nodered.org/t/multiple-5-serial-inputs-to-raspi-using-usb-ports/30659/3 "2020-08-07T16:24:52Z")

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