Em12 only using one antenna?

[liner66]

I've recently have had poor signal quality and am trying to find my problem. I have two yagis antennas. Am I correct by thinking the AT+QRSRP should show the status of both antennas?

AT+QRSRP
+QRSRP: -91,-140,-140,-140

[Viper67857]

Yeah, I'd check all my connections, especially the seating of the mhf4 connection on the board itself. Those numbers should be close to the same.

[Didneywhorl]

AT+QRSRP? Is actually a tough on. Ive run it with different antennas unplugged and the output wasn't very patternable. I never found good documentation for it. Honestly never looked hard, time poor.

[Didneywhorl]

Not to mention you have 2 antennas and 4 paramaters output there, funny thing its the same output as my em160. 4 numbers, one different than the other 3.

[liner66]

AT+QRSRP? Is actually a tough on. Ive run it with different antennas unplugged and the output wasn't very patternable. I never found good documentation for it. Honestly never looked hard, time poor.

Should AT+QCAINFO show more then one status? I just installed this em12 about a week ago and its worse then the em7455 I had before. The ping times has increased from 50-60 to 90+.

Edit from what i gathered AT+QRSRP listed the rsrp of antennas connected with -140 being no antenna.

[Viper67857]

Is the em12 in mbim mode? Mine came that way by default, but the pings are better in QMI mode.

As for the AT+QRSRP, mine normally shows
-~87,-~87,-140,-140. Sometimes one of the first two numbers will also read -140, but simply sending the command again will show the correct values. If you're consistently getting -140 on the div port then something isn't right. You didn't accidentally connect your 2nd mhf4 connector to the GPS port did you?

[liner66]

Is the em12 in mbim mode? Mine came that way by default, but the pings are better in QMI mode.

As for the AT+QRSRP, mine normally shows
-~87,-~87,-140,-140. Sometimes one of the first two numbers will also read -140, but simply sending the command again will show the correct values. If you're consistently getting -140 on the div port then something isn't right. You didn't accidentally connect your 2nd mhf4 connector to the GPS port did you?

I have both the M and D plugged in with G open. I have not changed from mbim.

[Viper67857]

That explains the pings.. As for the signal, have you tried unscrewing one antenna cable at a time to see if it goes away completely? That would tell if you're actually only receiving one feed or if the modem is just misreporting with the AT+QRSRP command.

[BillA]

MBIM is an older control interface for modems, while it's pretty universal, it's an extra layer for the data to go through, therefore increasing pings times. The newer QMI mode is the preferred method providing a more advanced and direct control over the modem with lower ping times and performance.

[liner66]

When I switch to QMI my ping gets even worse. Both of my antennas must be working I've unplugged one and left the other one plugged in and I never lose service. I'm still confused why my ping times with the em12 are worse then the em7455 =/

[Viper67857]

Connecting to different/worse bands maybe?

[liner66]

I'm band locked to b25. Is there a way to tell what tower im connected to? There is two towers in the same direction one is 3 miles away another is 9.

[gscheb]

I'm band locked to b25. Is there a way to tell what tower im connected to? There is two towers in the same direction one is 3 miles away another is 9.

https://wirelessjoint.com/viewtopic.php?f=31&t=705&hilit

[Didneywhorl]

When I switch to QMI my ping gets even worse. Both of my antennas must be working I've unplugged one and left the other one plugged in and I never lose service. I'm still confused why my ping times with the em12 are worse then the em7455 =/

Your EM12 is likely in MBIM mode. The EM7455 works best in QIM mode. These are communication protocols I believe.

Using the AT Command Terminal run the command

Code: Select all

AT+QCFG="usbnet"?

If it returns "2" your in MBIM, if it returns "0" your in QMI. This command only works on the Quectel modems, not the Sierra modems.

If you want to lower your ping and keep it in MBIM, you can adjust a file on the router; ask for details. My EM12s, EM20s, and EM160s run at 16-25ms ping using MBIM. I find that MBIM actually attains higher overall speeds versus using QMI when running Quectel modems. So far at least.

[The-Q]

If you want to lower your ping and keep it in MBIM, you can adjust a file on the router; ask for details. My EM12s, EM20s, and EM160s run at 16-25ms ping using MBIM. I find that MBIM actually attains higher overall speeds versus using QMI when running Quectel modems. So far at least.

I’m using an EM12-g and find MBIM provides better speeds than QMI. I’d be interested in the file you mentioned to lower ping times.

[Didneywhorl]

******
/sys/class/net/wwan0/cdc_ncm/tx_timer_usecs -->edit--> change from 400 to 0 when in MBIM mode will drop ping to less than half.
******

******
But if you open /usr/lib/rooter/connect/create_connect.sh and navigate to about line 770 you'll see a line:

# MBIM connect script
About 15 lines further on, we have a line:

ifup wan$INTER
I put the code:

MIFACE=$(uci get modem.modem$CURRMODEM.interface)
if [ -e /sys/class/net/$MIFACE/cdc_ncm/tx_timer_usecs ]; then
echo "0" > /sys/class/net/$MIFACE/cdc_ncm/tx_timer_usecs
fi
immediately after that line, and just before the line:

exit 0
To see subsequently if wwan0 (assuming a single modem) is set to zero, you can read the file like so at the shell prompt:

cat /sys/class/net/wwan0/cdc_ncm/tx_timer_usecs
******

[Didneywhorl]

This, above, is direct from the rooter forums.