Connect RM-502Q-GL to MT 3000

[Nazar]

Hello, i try to connect RM-502Q-GL to MT 3000 , however i receive error - Incompatible Modem . I could run AT command i see that it's works on usb2, but it's not connecting properly . Also i try to create new interface from luci with Protocol: QMI Cellular , but it's not working too. So i set rooter os to MT3000 and all works correct, so modem is ok.

My question is - could i connect it to gl inet firmware or i should have only Quectel modem from list Cellular - GL.iNet Router Docs 4 . ?

[Cathy]

Hello @Nazar

RM502Q is not fully compatible with GL.iNet firmware. So the GL.iNet web GUI displays it as a Incompatible Modem.
But the modem should be able to work. You can adjust the modem protocol and APN under cellular manual setup and try it again.

[Nazar]

Hi, thanks for response , that's the problem I could only use AT command

Here is logs
logread.tar (249.5 KB)
Sim is inserted, operator is connected and modem sees signal

[Cathy]

The log download failed. Is the modem set to QMI mode? Pls use AT+QCFG="USBNET" to check the mode.

Looks like your MT3000 is updated to FW v4.8. In FW v4.8, pls click "Sim Card Settings" to the settings page and modify the cellular settings, such as APN, protocol, etc.

[Nazar]

yes,

Sim card setting is not available sometimes and when it displays it's not clickable

However is see that sim is detected by modem

System log:
Tue Aug 5 07:37:59 2025 kern.info kernel: [ 32.640774] option 2-1:1.0: GSM modem (1-port) converter detected
Tue Aug 5 07:37:59 2025 kern.info kernel: [ 32.647105] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB0
Tue Aug 5 07:37:59 2025 kern.info kernel: [ 32.654233] option 2-1:1.1: GSM modem (1-port) converter detected
Tue Aug 5 07:37:59 2025 kern.info kernel: [ 32.660528] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB1
Tue Aug 5 07:37:59 2025 kern.info kernel: [ 32.667737] option 2-1:1.2: GSM modem (1-port) converter detected
Tue Aug 5 07:37:59 2025 kern.info kernel: [ 32.674185] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB2
Tue Aug 5 07:37:59 2025 kern.info kernel: [ 32.681417] option 2-1:1.3: GSM modem (1-port) converter detected
Tue Aug 5 07:37:59 2025 kern.info kernel: [ 32.687723] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB3
Tue Aug 5 08:17:10 2025 user.notice root: modem_traffic : ntp success...

For connecting modem to router I'm using https://www.waveshare.com/product/iot-communication/long-range-wireless/4g-gsm-gprs/usb-to-m.2-b-key.htm
logread_1.tar (255.5 KB)

[Cathy]

Please remove and reinsert the SIM card, then execute "AT+CFUN=0" and then "AT+CFUN=1" to try.

If modem not work in the QMI mode, you can set it to ECM or RNDIS mode. It should be able to work as a tethering device.

[Nazar]

Hi, on tethering mode it works good, however modem rebooting each few minutes without external power source.
Also cellular still want's to connect

So looks like it's problem with modem , thank you