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How to get up to date signal strength of Cellular Modem through ConnectCore6

+2 votes
Please see emails below.

In short, through 'mmcli -m 0' it will give you the signal strength once but will never updated it. I am looking a way that will continuously update it or to get the value from another place.

Steven


Hi Paolo,

Yes we are using the Digi XBee Cell 3G as well as the XBee3 Cell LTE CAT 1. Currently we are leaning more towards the XBee3 Cell LTE CAT 1.

I have tried with the mmcli to send AT commands with the following:
‘ccimx6sbc:~# mmcli -m 0 --command=+CSQ’
But I get the following error, which talks about not being in debug mode:
error: command failed: 'GDBus.Error:org.freedesktop.ModemManager1.Error.Core.Unauthorized: Cannot send AT command to modem: operation only allowed in debug mode’

I can see the signal strength in the ‘mmcli –m 0’, but is cached and never seems to change. Is there anyway to make it recent? Or any other suggestions to finding the signal strength?

/org/freedesktop/ModemManager1/Modem/0 (device id '46d35399ad120f4f16ad16fbde9594cf85fa6a47')
Hardware | manufacturer: 'Telit'
| model: 'LE866A1-NA'
| revision: '23.00.303 (M0A.30030)'
| supported: 'lte'
| current: 'lte'
| equipment id: '358832070047448'
System | device: 'Digi XBee Cellular'
| drivers: 'imx-uart'
| plugin: 'Telit'
| primary port: 'ttymxc4'
| ports: 'ttymxc4 (at)'
Numbers | own : 'unknown'
Status | lock: 'none'
| unlock retries: 'sim-pin (5), sim-pin2 (5), sim-puk (10), sim-puk2 (10)'
| state: 'connected'
| power state: 'on'
| access tech: 'lte'
| signal quality: '45' (cached)
Modes | supported: 'allowed: 4g; preferred: none'
| current: 'allowed: 4g; preferred: none'
Bands | supported: 'eutran-ii, eutran-iv, eutran-xii'
| current: 'eutran-ii'
IP | supported: 'ipv4, ipv6, ipv4v6'
3GPP | imei: '358832070047448'
| enabled locks: 'none'
| operator id: '302720'
| operator name: 'ROGERS'
| subscription: 'unknown'
| registration: 'home'
SIM | path: '/org/freedesktop/ModemManager1/SIM/0'

Bearers | paths: '/org/freedesktop/ModemManager1/Bearer/0'

As well for the LTE modem, I am using the following document for AT commands:
https://y1cj3stn5fbwhv73k0ipk1eg-wpengine.netdna-ssl.com/wp-content/uploads/2017/10/Telit_LE866-ME866_Series_AT_Commands_Refernce_Guide_r7.pdf

Regards,
Steven Marks


Hello Steven,

Are you referring to using the XBee Cellular with our ConnectCore 6?
Please confirm.

In general, when you use our XBee cellular with Yocto on the CC6, you will use the modem in bypass mode,
so you will *NOT* interface to the Digi commands, but to the modem OEM commands, so it depends on them.
That is exactly what Modem manager does (mmcli).

You could query “ATDB” to get signal strength with the Digi commands, but they are disabled in bypass mode, as I stated above:
https://www.digi.com/resources/documentation/Digidocs/90001541/#concepts/c_mode_bypass.htm?Highlight=bypass

Given you did not specify the product, I would assume you are using the XBee Cell 3G:
https://www.digi.com/products/xbee-rf-solutions/embedded-cellular-modems/digi-xbee-cellular-3g#specifications

In this case, the AT command manual for the U-blox U201 radio can be downloaded here: u-blox AT Commands Manual
https://www.u-blox.com/en/product/sara-u2-series#tab-documentation-resources

It looks like there are some specific commands for that:
The +CESQ and +CSQ AT commands are intended for the real-time evaluation of the signal strength and quality of the current cellular connection.

I hope this helps.

Best Regards,
Paolo Chiarlone


Hi Paolo,

I am trying to get a signal strength of the modem we have connected. I have set up the modem and have communicated through the cellular to the internet.

I found if I called ‘mmcli –m 0’, there is a line under ‘Status’ section called ‘signal quality’. After the value it says that value is cached. I moved the antenna around to the signal strength go up and down, but I noticed no change and suspected It must be cached at the star up.

I am wondering if there possibly to make the above value update continuously or another way to query the signal strength?

Regards,
Steven Marks
Embedded Software/Firmware Developer
asked Aug 29, 2018 in Linux by Steven Marks New to the Community (2 points)

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1 Answer

0 votes
Opened case #70262 about this
answered Aug 31, 2018 by PaoloC New to the Community (13 points)
edited Aug 31, 2018 by PaoloC
Hi Paolo,

I tried the following and got the below:

ccimx6sbc:~# iwpriv getRSSI
getRSSI   no private ioctls.

ccimx6sbc:~# cat /proc/net/wireless
Inter-| sta-|   Quality        |   Discarded packets               | Missed | WE
 face | tus | link level noise |  nwid  crypt   frag  retry   misc | beacon | 22
 wlan0: 0000    0     0     0        0      0      0      0      0        0

It seems those commands were for the Wifi and not for the Cellular.

Regards,
Steven
Steven,

This has nothing to do with the cellular radio.
This is for Wireless.

Paolo
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