# Quectel RG255C-GL 5G RedCap Quectel RG255C-GL is a compact, industrial-grade 5G RedCap module designed for mid-tier IoT applications. It supports 5G NR (SA) with LTE fallback, delivering download speeds up to 223 Mbps and upload up to 123 Mbps. The module offers global band support, integrated GNSS (GPS, GLONASS, Galileo, BeiDou, NavIC), and features ultra-low power consumption. Available in LGA, M.2, and Mini PCIe form factors, it supports a wide range of interfaces and is ideal for energy-efficient, reliable 5G connectivity across diverse devices. ![Quectel RG255C-GL 5G RedCap](https://3922449203-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M0mPxGpottOEfcucXOR%2Fuploads%2F0UufIQ8dNLTMaIJqHHm8%2FRG255CGL-mini-PCIe-3.png?alt=media\&token=add925a0-d7ca-4513-be0e-05b840c8beed) ### Quick Navigation * [Connect the Quectel RG255C-GL 5G ReadCap to Monogoto](#connect-the-rg255c-gl-5g-redcap-to-monogoto) * [Network Configuration](#network-configuration) * [Network Activation](#network-activation) * [Useful Links](#useful-links) ### Prerequisites * Monogoto SIM * Quectel RG255C-GL 5G RedCap cellular modem * Access to a private network ## Connect the RG255C-GL 5G RedCap to Monogoto {% hint style="info" %} When connecting to the RG255C-GL 5G RedCap modem, keep the [**AT Commands manual**](https://files.gitbook.com/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M0mPxGpottOEfcucXOR%2Fuploads%2F1v69Xch2tGnYpO5Vi1ws%2Fquectel_rg255c_seriesrm255cgl_at_commands_manual_v1.0.pdf?alt=media\&token=285cc448-0687-41ae-816e-1282b6b9ddad) next to you to look up details about commands. {% endhint %} **Connect to the modem**, enter the command: `AT` and wait for the response: `OK` {% hint style="info" %} When using Windows, [install the driver ](https://files.gitbook.com/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M0mPxGpottOEfcucXOR%2Fuploads%2F3daVAM4FpqNWdz6CazYV%2Fquectel_windows_usb_driverq_ndis_v2-8_en.zip?alt=media\&token=d8e52119-8aea-4701-9d8b-c09c1505daee)using the disk or USB stick provided by Simcom. {% endhint %} **Reset the modem** to the factory default configuration: ```bash AT+CFUN=1,1 ``` Set the error reporting to **verbose**, resulting in more descriptive error messages (optional): ```bash AT+CMEE=2 ``` Check if the SIM card is attached and is not locked with a PIN, expected response: `+CPIN: READY`: ```bash AT+CPIN? ``` {% hint style="warning" %} If you receive an error, the SIM may not be inserted properly or the SIM is protected with a PIN. By default, Monogoto SIMs are not PIN protected. {% endhint %} ### Query device information Request the modem **hardware version**: ``` AT+CGMM ``` Request the modem **firmware version**: ```bash AT+CGMR ``` response: ``` +CGMR: RG255CGLABR01A04M4G_BETA250513A ``` Request the **IMSI** (International Mobile Subscriber Identity): ``` AT+CIMI ``` Request the **ICCID** (Integrated Circuit Card ID), which is the identification number of the SIM card ```bash AT+ICCID ``` ### **Network mode preference**. **Manually set the preference mode**: * `AT+QNWPREFCFG="mode_pref",LTE:NR5G` → Enables 5G NR along with LTE, UMTS, and GSM (multi-mode operation). * `AT+QNWPREFCFG="mode_pref",LTE` → Typically enables LTE/UMTS/GSM only (no 5G). To **test** if the network is set correctly enter: ``` AT+QNWPREFCFG="mode_pref" ``` Expected response: `+QNWPREFCFG: "mode_pref",AUTO` ### Network Configuration **Manually set the network**: Monogoto's private LTE network is indicated with the **MCCMNC** code: `99974`. To connect to the private LTE network, enter: ``` AT+COPS=1,2,"99974",11 ``` To **test** if the network is set correctly enter: ``` AT+COPS? ``` Expected response: +COPS: 0,0,"Monogoto5G 99974",11 `11` indicates that the modem is using 5G SA. **Check the radio signal strength and signal quality:** ```bash AT+CSQ ``` Example response: `+CSQ: 22,1` {% hint style="info" %} `+CSQ` returns 2 values separated by a comma. The first value represents the **signal strength** and provides a value between 0 and 31; a higher number indicates better signal strength. The second value represents the **signal quality** indicated by a value between 0 and 7, a lower value indicates better signal quality . If `AT+CSQ` returns `99,99`, the signal is undetectable or unknown. {% endhint %} ### Network Activation **Set the APN to** `data.mono`: ``` AT+CGDCONT=1,"IP","data.mono" ``` To **test** if the APN is set correctly, enter: ``` AT+CGDCONT? ``` Expected response: `+CGDCONT: 1,"IP","data.mono","0.0.0.0",0,0,0` **Activate the PDP (packet data protocol) context:** ``` AT+CGACT=1,1 ``` **Test** if the PDP context is activated: ``` AT+CGACT? ``` Expected response: `+CGACT: 1,1` #### Request Serving Cell Information ``` AT+QENG="servingcell" ``` Example response: ``` +QENG: "servingcell","NOCONN","NR5G-SA","TDD",999,74,000004001,5,2,638592,78,3,-66,-10,28,1,49 ``` * `99974` (the fourth value) indicates that the device being connected to Monogoto's Private LTE Network * `78` represents the cellular band the modem is currently using #### Validate if your device received an **IP address**: 
AT+CGPADDR
Expected response: `+CGPADDR: 1,10.XXX.XX.XXX` ### Test the connection by sending a PING A PING test can be performed to test if the modem has an active data connection with a mobile network. When cellular modems are idle for a long period of time, cell towers might drop the data connection to save resources. Sending regular PINGs is a good method for testing the data connection, as well as for keeping the connection alive because the operator registers your device as being actively used. **Send 4 PINGs** to IP address `8.8.8.8`: ``` AT+QPING=1,"8.8.8.8",4 ``` Example response: ``` +QPING: 0,"8.8.8.8",32,16,255 +QPING: 0,"8.8.8.8",32,14,255 +QPING: 0,"8.8.8.8",32,15,255 +QPING: 0,"8.8.8.8",32,17,255 ``` {% hint style="success" %} Do you see an IP address? **Congratulations!** 🎉 **You’ve successfully connected the Quectel RG255C-GL 5G RedCap to Monogoto.** \ Have a look at the **Things** logs in the [**Monogoto Console**](https://console.monogoto.io/) to find more details about the established connection. {% endhint %} ## Useful Links * [Quectel RG255C-GL 5G RedCap AT Commands ](https://files.gitbook.com/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M0mPxGpottOEfcucXOR%2Fuploads%2F1v69Xch2tGnYpO5Vi1ws%2Fquectel_rg255c_seriesrm255cgl_at_commands_manual_v1.0.pdf?alt=media\&token=285cc448-0687-41ae-816e-1282b6b9ddad) * [Quectel RG255C-GL 5G RedCap product page](https://www.quectel.com/product/5g-redcap-rg255c-series/) * [Quectel RG255C-GL 5G RedCap Hardware Design](https://files.gitbook.com/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M0mPxGpottOEfcucXOR%2Fuploads%2Fl1vBTkyRYDjUHqeyPGo3%2Fquectel_rg255cgl_mini_pcie_hardware_design_v1.0.pdf?alt=media\&token=96ebc796-03ff-40cf-b97d-07548b12ee78) * [Quectel RG255C-GL 5G RedCap module\_specification](https://files.gitbook.com/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M0mPxGpottOEfcucXOR%2Fuploads%2FUzo0m4IgKyLPqsDn3oxA%2Fquectel_rg255cgl_mini_pcie_5g_module_specification_v1.1.pdf?alt=media\&token=ed648d44-5f62-4436-973d-638184e47a91)