# VOXLFlight LTE modem

Source: https://forum.modalai.com/topic/697/voxlflight-lte-modem
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2022-02-01 14:39:14 UTC by relevinsky
Replies: 5 · Views: 722

## relevinsky · 2022-02-01 14:39:14 UTC

Hi,
I have several questions:
1) What's reason that by voxl-inspect-services I see, that :
voxl-modem
voxl-qvio-server
voxl-vision-px4 
are in "Not running" state, while the services were configured and I received "approving for it enabling and starting" -
"enabling  voxl-qvio-server systemd service
 starting  voxl-qvio-server systemd service
 Done configuring voxl-qvio-server"

2)How could i know if voxl flight is LTE server or client?

3)Is it possible to configure LTE v2 modem except of "voxl-configure-modem"?(AT commands)

Thanks,

## Reply by Guest · 2022-02-01 21:08:46 UTC

Hi, 

If the voxl services were marked as enabled but not running that means that they were stopped for one of two reasons: A) you ran them manually in a terminal window which killed the background process since only one instance can run at a time or B) they encountered some sort of error. If the ran into an error you can check the output logs from the services using ``` journalctl -u voxl-qvio-server``` or ```journalctl -u voxl-vision-px4```. If they crashed due to an error, the info as to why will be there and posting those logs will allow us to help further. 

I can't speak to the modem configuration stuff but i'll ping someone who can.

Thanks,

Alex

## Reply by tom (ModalAI staff) · 2022-02-01 21:21:26 UTC

@relevinsky For `voxl-modem` depending on what configuration is set up, the background service may exit. This could be due to a failure, or it may be a successful exit if it finished running everything it needed to.

Once the modem is brought up, you can send AT commands to `/dev/ttyUSB2` using something similar to: 

`echo -ne "AT+QENG=\"servingcell\"\r" | busybox microcom -t 1000 /dev/ttyUSB2`

This exact AT command isn't supported on Sierra modems but using this same format of piping a command to microcom will work.

Here is a link to a Sierra doc about which AT commands are supported on 76** modems: https://source.sierrawireless.com/resources/airprime/software/airprime_wpx5xx_wp76xx_wp77xx_at_command_reference/

## Reply by relevinsky · 2022-02-02 14:09:50 UTC

@Alex-Gardner said in [VOXLFlight LTE modem](/post/3218):
> journalctl -u voxl-qvio-server

Thank you for your answer.
I found a problem:
"loading qvio config file
Error in json_read_file while parsing file /etc/modalai/voxl-qvio-server.conf"
I made only voxl-configure-qvio ,the broken file is created after that (i think)
Could you help me to solve a problem?
Thanks

## Reply by relevinsky · 2022-02-02 14:12:42 UTC (in reply to tom)

@tom 
Thank you.
How could i know wherever voxl flight is LTE server or client?
Thanks,

## Reply by Eric Katzfey (ModalAI staff) · 2022-02-02 16:33:27 UTC (in reply to relevinsky)

@relevinsky What do you mean by LTE server / client? LTE is a cellular technology that will provide your Voxl flight with Internet access.