Need help with RM502Q-AE

[Haze69]

Hey everyone,

I really need some help setting up my RM502Q-AE. I currently have the modem on a USB enclosure and trying to set it up on Visible. When connecting to my linux machine, if I create a mobile connection with APN VSBLINTERNET it just keeps spinning. When I put in my Verizon SIM card and use APN vzwinternet, it connects right away and works. The Visible SIM card does work when putting it into my iPhone and It was activated as byod so it doesnt have any IMEI assigned to the account so it "should" work as easily as the Verizon.

I tried following this post: https://wirelessjoint.com/viewtopic.php?t=1703

"Before you start this might want to set back to OEM state if you been putting other commands in to start off fresh."

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AT+QPRTPARA=3 (modem to its OEM state)

AT+QMBNCFG="AutoSel",0 (stop Autoselect config on sim detection)
AT+QMBNCFG="Deactivate" (disable MBN config)
AT+CFUN=1,1 (reboot the modem)
AT+QCFG="usbnet",2 ( MBIM protocol)
AT+QCFG="nwscanmode",3,1 ( 4G-LTE only)
AT+CGDCONT=1,"IPV6","VSBLINTERNET" (Has to be ipv6 only)

All commands came back OK except

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AT+QCFG="nwscanmode",3,1

which said ERROR.

However, still no luck in getting the connection active. To further troubleshoot, I setup a Raspberry Pi with Rooter and things only got more complicated. I am not able to get neither Verizon or Visible to connect within Rooter and under AT Commands " cannot open device /dev/ttyusb2" is the error I keep getting. The only way I am able to push AT Commands is on my Linux laptop. I have reinstalled Rooter multiple times and I have not been able to get AT Commands to work within Rooter. I have set the APN for both Verizon and Visible and neither are able to activate.

I have researched for days now hoping to figure this out but have not been successful. I would appreciate any help any of you can provide.

Thanks in advance

[Didneywhorl]

If you ran the command AT+QPRTPARA=3, make sure you run the command AT+QPRTPARA=1, otherwise you may have memory issues.

Also, dont run that command again. It isn't necessary, and it can be harmful to the modem.


The RM50xQ series are modems that have many more commands not previously used by Quectel modems.

Ill have to lookup the regular commands I run.

[Haze69]

Ok thank you, I ran the command as you suggested. Do you have any other recommendations on how I can get this to work either with Rooter - OpenWRT or natively within Linux?

[Haze69]

After days of troubleshooting and trying the modem on different devices, I was able to get it working with Visible. Hopefully this can help anyone else experiencing a similar problem. Using a Linux computer I pushed all the AT commands posted above from the guide except for

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AT+QCFG="nwscanmode",3,1 ( 4G-LTE only)

It appears that command has been replaced with

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AT+QNWPREFCFG="mode_pref",LTE

The modem now works connected via USB in linux as mobile broadband and connected to a Raspberry Pi running OpenWRT.

[Didneywhorl]

Got a little behind.

Sorry for the delay here...

I usually try to run the following on all my RM50x modems:

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AT+QNWCFG="dss_enable",1

AT+QNWPREFCFG="mode_pref",Auto

AT+QNWPREFCFG="us_usage_setting",1

I really don't like to lock bands, but with these new modems the band masking is super easy.

Mode_pref I prefer to leave at auto, never lock it to 5GNR so far. Doesn't like it.

dss-enable is new and seems to not hurt to enable, but sometimes does hurt to have disabled. Not sure how to know when its needed. You can google 5GNR DSS for more info as to what it is(Dynamic Spectrum Sharing).

[Haze69]

Since this modem does 7xca, is it even necessary to lock bands? Would I see any benefit from locking bands over allowing the modem to automatically carrier aggregate?

Also, what does

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AT+QNWPREFCFG="us_usage_setting",1

command do?

[Didneywhorl]

The command seems to meet the network requirements for networks that require voLTE support of devices on the network.


I would only lock bands if the band itself is causing issues. Otherwise I never lock bands.

[pstephens]

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AT+QNWPREFCFG="us_usage_setting",1

Shouldn't this be

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AT+QNWPREFCFG="ue_usage_setting",1

?

Here's the output from my RM502Q:

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AT+QNWPREFCFG=?
+QNWPREFCFG: "gw_band",B1:...:BN
+QNWPREFCFG: "lte_band",B1:...:BN
+QNWPREFCFG: "nsa_nr5g_band",B1:...:BN
+QNWPREFCFG: "nr5g_band",B1:...:BN
+QNWPREFCFG: "mode_pref",RAT1:...:RATN
+QNWPREFCFG: "srv_domain",(0-2)
+QNWPREFCFG: "voice_domain",(0-3)
+QNWPREFCFG: "roam_pref",(1,3,255)
+QNWPREFCFG: "ue_usage_setting",(0,1)
+QNWPREFCFG: "policy_band"
+QNWPREFCFG: "ue_capability_band"
+QNWPREFCFG: "rat_acq_order",RAT1:...:RATN
+QNWPREFCFG: "nr5g_disable_mode",(0-2)

OK

[Didneywhorl]

Shouldn't this be

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AT+QNWPREFCFG="ue_usage_setting",1

?

...

Correct.

Since this modem does 7xca, is it even necessary to lock bands? Would I see any benefit from locking bands over allowing the modem to automatically carrier aggregate?

Also, what does

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AT+QNWPREFCFG="us_usage_setting",1

command do?

Sets the modem to support VoLTE.

[Time-Pilot]

The other commands that have helped me with Visible are

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AT+QMBNCFG="List"
AT+QMBNCFG="Select","ROW_Generic_3GPP"

Use the exact "ROW_Generic_3GPP_XXXXXX" you get from the list command.