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WM21 4G Cat M/NB Modem


WM21 is a 4G Modem designed to provide cat M or cat NB access to the RS232 equipment. It comes with 1*RS232 port, 1*USB Type-C port, 1*Sim Slot and 1*Cellular Antenna interface. WM21 supports both RS232 communication and power supply via an ethernet cable. With delicate design, WM21 is especially applicable to the metering industry.


·1*RJ45 + LTE + 1*USB + 1*SIM Slot + 1*4G Antenna

·RS232 communication and power supply via one RJ45 interface

·IP21 Design

·Support Dying Gasp

·Local and Remote Device Management


Hardware Interface

·1 * RJ45 for RS232 and Power Supply

·1 * USB Type-C

·1 * External 4G Antenna

·1 * Sim Slot

·1 * Grounding Interface

·1 * Reset Button

·LED: Power, LTE, DATA, Alarm, Signal


Data Features

·Cellular Access

    Cat-M1(Power Class 3) :

 B1/B2/B3/B4/B5/B8/B12/B13/B18/B19/B20/B 25/B26/B27/B28/ B66/B73/B85;

    Cat-NB2 (Power Class 3) :

 B1/B2/B3/B4/B5/B8/B12/B13/B18/B19/B20/B 25/B26/B28/B66/ B73/B85;

    Cat-M1& Cat-NB2(Power Class 2) :


    APN Management

    RAT mode Lock

    Band Lock


·RS232 Serial Communication

    Server or Client mode

    TCP Port Configurable









    Auto Reboot on Error

·Periodic Ping / Reboot



·Surge Protection

·Dying Gasp



·Local and Remote Management

    WEB, CLI, SNMPv3

·Diagnostic: Ping, Tcpdump

·Zero-touch Provision


·Compatible OS:

    Windows XP/7/8 or higher




·Dimension: 70mm*60mm*24.5mm

·Weight: 135g

·IP21 Design

·Material: ABS Plastic Case

·Power consumption: ≤5W

·Input: DC 4-23V

·Operating temperature: -10~+75°C

·Operating humidity: 10~95%RH

·Store temperature: -40~+85°C

·Installation: Desktop


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