# Set a USB device to always be /dev/ttyUSB1
**URL:** https://discourse.nodered.org/t/set-a-usb-device-to-always-be-dev-ttyusb1/61860
**Category:** General
**Created:** [27 April 2022 09:43 UTC](https://discourse.nodered.org/t/set-a-usb-device-to-always-be-dev-ttyusb1/61860 "2022-04-27T09:43:19Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@swanside](https://discourse.nodered.org/u/swanside)
#### Post date: [27 April 2022 09:43 UTC](https://discourse.nodered.org/t/set-a-usb-device-to-always-be-dev-ttyusb1/61860/1 "2022-04-27T09:43:20Z")
Hello.
I have 2 USB devices on my Raspberry PI, both Modbus as 1 reads my Solar equipment and the other reads an energy meter. At midnight my Pi reboots, and every so often I have to go into Node Red to change the /dev/ttyUSB1 to /dev/ttyUSB0 for my Solar equipment and then /dev/ttyUSB0 to /dev/ttyUSB1 for my energy meter. Is there a way that I can make /dev/ttyUSB1 to always be the same device please?
Thanks
Paul
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### Author:  [@ghayne](https://discourse.nodered.org/u/ghayne)
#### Post date: [27 April 2022 10:56 UTC](https://discourse.nodered.org/t/set-a-usb-device-to-always-be-dev-ttyusb1/61860/2 "2022-04-27T10:56:35Z")
Have a look here:
[https://www.domoticz.com/wiki/PersistentUSBDevices](https://www.domoticz.com/wiki/PersistentUSBDevices)
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### Author:  [@ghayne](https://discourse.nodered.org/u/ghayne)
#### Post date: [27 April 2022 10:59 UTC](https://discourse.nodered.org/t/set-a-usb-device-to-always-be-dev-ttyusb1/61860/3 "2022-04-27T10:59:50Z")
A question - Why do you reboot at midnight?
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### Author:  [@marcus-j-davies](https://discourse.nodered.org/u/marcus-j-davies)
#### Post date: [27 April 2022 12:23 UTC](https://discourse.nodered.org/t/set-a-usb-device-to-always-be-dev-ttyusb1/61860/4 "2022-04-27T12:23:00Z")
I don't know if this applies.
but if these are serial devices - they will have a static entry in `/dev/serial/by-id`
so rather then pointing to `/dev/ttyUSBX` point it to its
corresponding ID. `/dev/serial/by-id/xx-xx-xx`
These ID's don't change and they are symlinks to `/dev/ttyUSBX`
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### Author:  [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)
#### Post date: [27 April 2022 14:14 UTC](https://discourse.nodered.org/t/set-a-usb-device-to-always-be-dev-ttyusb1/61860/5 "2022-04-27T14:14:31Z")
That was going to be my recommendation as well. That's how I've set up my two USB serial devices. Much easier and saves you faffing with setup.
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### Author:  [@ghayne](https://discourse.nodered.org/u/ghayne)
#### Post date: [27 April 2022 14:44 UTC](https://discourse.nodered.org/t/set-a-usb-device-to-always-be-dev-ttyusb1/61860/6 "2022-04-27T14:44:29Z")
> [@marcus-j-davies](#):
>
> I don't know if this applies.
It does! I had forgotten this! Works fine with me.
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### Author:  [@swanside](https://discourse.nodered.org/u/swanside)
#### Post date: [27 April 2022 14:46 UTC](https://discourse.nodered.org/t/set-a-usb-device-to-always-be-dev-ttyusb1/61860/7 "2022-04-27T14:46:11Z")
Thanks all. Will help me out that.
I just have a midnight boot on it as sometimes it becomes really slow to access remotely and found a reboot helps it out
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### Author:  [@ncherry](https://discourse.nodered.org/u/ncherry)
#### Post date: [27 April 2022 15:06 UTC](https://discourse.nodered.org/t/set-a-usb-device-to-always-be-dev-ttyusb1/61860/8 "2022-04-27T15:06:01Z")
A word of warning on USB devices. Some cheap clone serial donges don't have a serial number (and I think that can't add one either) so they just get added by the Linux sub-system in the order they respond. Real serial dongle have a serial number and each is unique so they can be properly handled by the USB subsystem.
Note: serial number != serial port. 🙂
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### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [26 June 2022 15:06 UTC](https://discourse.nodered.org/t/set-a-usb-device-to-always-be-dev-ttyusb1/61860/9 "2022-06-26T15:06:47Z")
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