6.2 Modem Connection

Guidance to verify the physical connections and virtual interfaces of the mobile modem device.

6.2.1 - Physical Connections

Use the included tool hex wrench to lose all of the four pieces hexagon bolts on the front side of the EZR23 router then open the case. You can find the Mobile Modem, on the top left corner on the below image.

The Quectel mobile modem has three IPEX connectors, including Main, GNSS, and DIV. The Main connector goes to the main mobile antenna on the top left side, and the DIV connector goes to the alternative mobile antenna on the top right side. Both of them use thinner jumper cables, comparing with the Wi-Fi antenna cables.

‌ To ensure the mobile modem installed correctly, check the below subjects:

• Check if above Main & Div sockets connect to the correct mobile antennas.

• Check if the attached jumper cables connect tightly.

• Check if the two pieces screws nearby the jumper cable installed correctly.

• Touch the top cover on the mobile modem and test if its too hot temperature.

*GNSS socket is for connecting to a GPS antenna. *On Sierra Wireless modems, the alternative mobile socket is AUX, and the GPS antenna socket is GPS.

To avoid distort or break the IPEX connectors on the mobile modem, do not reconnect the jumper cables unless the router is malfunctioning.

6.2.2 - Virtual Interfaces

When the mobile modem correctly installed and the router is powered on, go to command-line interface to check the virtual interfaces created by the mobile modem. The Mobile interface uses one of the virtual interfaces to set up the internet connection.

After accessing the command-line interface, use command ls /dev to check all the virtual interfaces on the EZR23 router. Check the return value and find if the router has below two interfaces. If unable to locate these interfaces, recheck the above 6.2.1 physical connections.

• cdc-wdm0: Use by the QMI-cellular protocol

• ttyUSB2: Use by the 4G-PPP protocol

root@OutdoorRouter:~# ls /dev
bus                 memory_bandwidth    mtd4ro              mtdblock5           random              ttyS15              ttyUSB1
cdc-wdm0            mtd0                mtd5                mtdblock6           shm                 ttyS2               ttyUSB2
console             mtd0ro              mtd5ro              net                 tty                 ttyS3               ttyUSB3
cpu_dma_latency     mtd1                mtd6                network_latency     ttyS0               ttyS4               urandom
full                mtd1ro              mtd6ro              network_throughput  ttyS1               ttyS5               watchdog
gpiochip0           mtd2                mtdblock0           null                ttyS10              ttyS6               zero
gpiochip1           mtd2ro              mtdblock1           port                ttyS11              ttyS7
hwrng               mtd3                mtdblock2           ppp                 ttyS12              ttyS8
kmsg                mtd3ro              mtdblock3           ptmx                ttyS13              ttyS9
log                 mtd4                mtdblock4           pts                 ttyS14              ttyUSB0