Milesight UR41 4G Cat 4 Mini Industrial Router with GPS

Milesight UR41 (UR41-L08EU) – 4G Cat 4 mini industrial router with GPS and serial I/O

The Milesight UR41 (UR41-L08EU) is a 4G LTE Cat 4 industrial router in a palm-sized metal enclosure measuring 70 x 55 x 22 mm and weighing 103 g. It supports RS232 or RS485 serial communication, galvanically isolated digital I/O, and GPS/GNSS positioning – all within a device rated to -40 to +60 °C and IP30. Power arrives via a 5-24 V DC terminal block or 5 V USB Type-C, making it equally at home on a 12 V DC rail, a USB power bank, or a solar-charged battery system.

The UR41 uses a hardware watchdog and automated failover between cellular and Ethernet to maintain uptime without manual intervention. VPN tunnels cover IPsec, OpenVPN, WireGuard, GRE, DMVPN, and ZeroTier. Modbus RTU, Modbus TCP, and DLMS/COSEM run natively over the serial port. Remote management runs through Milesight DeviceHub for bulk configuration and firmware updates, and MilesightVPN for direct secure access to field devices.

Key features

• 4G LTE Cat 4 with fallback: Up to 150 Mbps download and 50 Mbps upload, with automatic fallback to 3G WCDMA and 2G GSM.
• GPS and multi-constellation GNSS: GPS, GLONASS, BeiDou, Galileo, and QZSS with 2.5 m CEP open-air accuracy. Position data readable via serial port, MQTT, TCP client/server, or UDP.
• Software-switchable serial port: One port configures as RS232 or RS485 via the web interface. Supports Modbus RTU/TCP client, Modbus gateway, transparent TCP/UDP, and DLMS client.
• Galvanically isolated digital I/O: One DI (dry contact) and one DO (wet contact, max 0.3 A at 30 V DC) on a 3.5 mm terminal block. Triggerable via DI state, SMS, CLI, Modbus, or MQTT.
• Low power consumption: Standby mode draws 6.3 mA at 12 V. Idle mode draws 70 mA at 12 V. Data link draws 157 mA at 12 V. Supports scheduled wake, SMS wake, and DI wake.
• Dual power input: 5-24 V DC on a 2-pin terminal block with surge protection and reverse polarity protection, plus 5 V/1 A via USB Type-C for bench testing or USB-powered installs.
• Hardware watchdog: Built-in watchdog automatically recovers from software lockup, cellular failure, and network outage without remote intervention.
• Full VPN suite: IPsec (multiple clients and server), OpenVPN (multiple clients and server), WireGuard, GRE, L2TP, PPTP, DMVPN spoke, and ZeroTier.
• Milesight DeviceHub management: Centralised dashboard for status monitoring, bulk configuration, and remote firmware update across multiple UR41 units.
• Compact industrial enclosure: Metal housing, IP30, -40 to +60 °C operating range. DIN rail, wall mount, and desktop mounting supported.

What is the Milesight UR41 used for?

Smart metering and DLMS/COSEM integration

The UR41 supports DLMS/COSEM client mode over the serial port, making it a direct fit for smart meter head-end communications. Electricity and gas meters using IEC 62056 over RS232 or RS485 connect without a protocol converter. The router forwards meter data upstream via MQTT or HTTPS to Azure IoT Hub, AWS IoT Core, or a custom SCADA head-end.

Remote substation and grid monitoring

For distribution substations and remote grid assets, the UR41 provides the cellular uplink alongside serial connectivity to protection relays, RTUs, and PLCs using Modbus RTU or Modbus TCP. The digital input can monitor door contact or alarm relay status. GPS time-stamping is available for event correlation across distributed sites.

Vending machines and unattended retail

The UR41 was developed partly for vending machine connectivity – a use case that demands low standby power, RS232 to the vend controller, remote reboot capability via SMS or DI, and a small footprint that fits inside existing enclosures. The USB Type-C power input suits installations where only a USB supply is available inside the machine.

Industrial equipment and robotics

PLCs, servo controllers, and robotic cells communicating over RS485 Modbus RTU can connect directly to the UR41 serial port. The router bridges Modbus RTU to Modbus TCP for SCADA integration, or routes data to cloud platforms including ThingWorx and AWS IoT Core. The galvanic isolation on the DI/DO protects against ground loop faults common in motor-heavy environments.

Mobile and vehicle-mounted IoT

The combination of GPS/GNSS positioning and 4G cellular in a 103 g enclosure suits vehicle-mounted or portable IoT applications. Position data transmits via MQTT or TCP alongside sensor or equipment data from the RS485 port. Power from a 12 V vehicle supply connects directly to the DC terminal block.

Solar and battery-powered remote sites

Standby power draw of 6.3 mA at 12 V makes the UR41 viable on small solar-charged battery systems. Scheduled wake and DI-triggered wake mean the router can sleep between reporting intervals and wake on an alarm input, keeping average current well below the standby figure across a full day.

Pro tip: use the DI wake to extend battery life on remote sites

If the UR41 is on a battery-backed supply and only needs to report periodically, configure a scheduled wake interval in the power management settings alongside a DI wake trigger for alarm conditions. The router sleeps at 6.3 mA, wakes on schedule or on a monitored alarm input, transmits data, and returns to standby. On a 12 V 7 Ah battery with a modest solar panel, this approach can run a remote monitoring node indefinitely. Standby and idle modes are configured in the web interface under System > Power Management.

UR41 vs UR41L: which variant to choose?

The UR41 (UR41-L08EU) and the UR41L (UR41L-L0CEU) share the same enclosure, processor, memory, serial port, DI/DO, and management platform. The differences are in the cellular module and positioning capability.

For deployments in the UK and Europe where 3G networks remain in service and GPS positioning adds operational value, the UR41-L08EU is the stronger choice. The UR41L-L0CEU suits purely fixed, cost-sensitive M2M applications where 10 Mbps Cat 1 throughput is sufficient and positioning is not required.

Frequently asked questions

Does the Milesight UR41 have Wi-Fi?

No. Neither the UR41 (UR41-L08EU) nor the UR41L (UR41L-L0CEU) has Wi-Fi. The router provides 4G cellular as its WAN and one 10/100 Mbps Ethernet LAN port for wired device connection. If Wi-Fi is a requirement, the Milesight UR32 or UR35 series are the relevant alternatives in the Milesight range.

What SIM card does the Milesight UR41 take?

The UR41 uses a single Nano SIM (4FF) slot. The SIM tray is on the side panel and requires the ejector tool supplied in the box. The router does not support hot-swapping – power it down before inserting or removing the SIM. For fixed installations requiring inbound VPN connections or a static address, a fixed IP SIM card removes the carrier-grade NAT barrier.

How is the Milesight UR41 powered?

The UR41 accepts 5-24 V DC on a 2-pin 3.5 mm terminal block, with built-in surge protection and reverse polarity protection. It also accepts 5 V at 1 A via the USB Type-C port, which is useful for bench testing or installations where only USB power is available. The DC terminal block route is recommended for permanent installations because it covers 12 V and 24 V DC supplies directly without a converter.

What serial protocols does the UR41 support?

The single serial port switches between RS232 and RS485 in software. Supported modes include Modbus RTU client, Modbus TCP client, Modbus gateway (RTU to TCP bridging), DLMS client for smart meter communication, and transparent serial over TCP or UDP. Baud rates from 300 bps to 230400 bps are supported. The terminal resistor switch for RS485 is on the device hardware.

What is Milesight Development Platform and does the UR41 support it?

Milesight Device Platform is a cloud-based device management platform for Milesight routers. It provides centralised status monitoring, remote configuration, bulk firmware updates, and alert management across multiple devices. The UR41 supports Milesight MDP alongside MilesightVPN, which gives engineers direct secure tunnel access to devices and equipment connected behind routers in the field. Both are included with no additional hardware required.

What is the operating temperature of the Milesight UR41?

The UR41 operates from -40 to +60 °C. This covers outdoor cabinet and vehicle applications in UK and European climates without additional thermal management in most cases. Storage temperature extends to +85 °C.

Can the Milesight UR41 connect to AWS IoT Core or Azure IoT Hub?

Yes. The UR41 firmware includes native support for AWS IoT Core (with Jobs support) and Azure IoT Hub. Data from connected serial devices or digital I/O can route directly to cloud IoT platforms via MQTT or MQTTS without a separate edge gateway. MQTT broker and client modes are both supported locally on the router.

Related products and further reading

The UR41-L08EU sits within our broader Milesight router range, which includes the UR32 and UR35 series for deployments needing dual SIM, Wi-Fi, or higher port counts. For the SIM card, a fixed IP SIM is strongly recommended for any installation requiring inbound VPN access or remote management without dynamic DNS workarounds. Our range of 4G antennas includes options for external mounting where the stub antenna supplied in the box is insufficient – particularly relevant for metal enclosure or sub-panel installations.