Robustel R1511e

Robustel R1511e – Compact Industrial 4G LTE eSIM Router

The Robustel R1511e is a compact industrial 4G LTE router with a fully embedded MFF2 eSIM, supporting global LTE, 3G, and 2G frequencies from a single hardware platform. It connects Ethernet and serial RS-232 or RS-485 equipment over cellular, with automatic failover, a built-in Modbus RTU to TCP gateway, and optional 2.4 GHz Wi-Fi. The R1511e is available in two variants: RS-232 serial port (model R1511e-4L-A35GL-A) or RS-485 serial port (model R1511e-4L-A35GL-B).

The key differentiator is the MFF2 eSIM. Unlike physical SIM routers, the R1511e stores up to 6 operator profiles and switches between them over the air via RCMS cloud management. If a profile activation fails, the router automatically rolls back to the last working profile. RobustVPN provides a fixed IP address on any active eSIM profile, removing the need for a separate fixed IP SIM card in most deployments.

Key Features

• Global 4G LTE Cat 4 via embedded MFF2 eSIM – LTE FDD B1/2/3/4/5/7/8/12/13/18/19/20/25/26/28/66, LTE TDD B38/39/40/41, 3G WCDMA, 2G GSM
• GSMA SGP.22 compliant – up to 6 eSIM profiles, remote download, activation, switching, and failsafe rollback
• 2 x 10/100 Mbps Ethernet – configurable as dual LAN or 1x LAN + 1x WAN with 1.5 kV magnetic isolation
• 1 x RS-232 or RS-485 serial port (hardware configured) with built-in Modbus RTU to TCP gateway
• 2.4 GHz Wi-Fi 802.11 b/g/n in AP and client modes, WPA3 security
• IPsec, OpenVPN, GRE, and WireGuard VPN tunnels
• RobustVPN fixed IP address on any eSIM profile – no fixed IP SIM required
• Automatic failover across 4G, Ethernet, and Wi-Fi connections
• RCMS cloud platform for remote monitoring, configuration, and eSIM profile management
• DIN rail, wall, and desktop mounting – -25 to +70°C operating temperature, IP30
• RobustOS with SDK support – C and C++ development environment, 64 MB RAM / 4 MB flash available
• CE, UKCA, FCC, IC, RCM certified

Applications

Remote PLC and Controller Connectivity

The R1511e connects PLCs, variable speed drives, and legacy controllers with RS-232 or RS-485 serial ports directly to IP networks via cellular. The built-in Modbus RTU to TCP gateway translates serial Modbus traffic without any changes to upstream SCADA or HMI software. This makes it a direct replacement for fixed-line serial connections in water treatment plants, substations, and manufacturing sites where running new cabling is not practical.

EV Charge Point Monitoring

Many EV charge points use OCPP over Ethernet or require a cellular backhaul where fixed broadband is unavailable. The R1511e provides a compact cellular gateway with dual Ethernet ports and automatic failover, keeping charge points connected to back-office management systems. The eSIM removes the need to pre-provision SIM cards across large charge point rollouts – profiles are assigned and activated remotely after installation.

Retail and Vending Machine Connectivity

Vending machines, parcel lockers, and payment terminals typically use RS-232 or Ethernet to communicate with host systems. The R1511e provides cellular backhaul with a fixed IP address via RobustVPN, enabling secure remote access and transaction processing without a fixed broadband connection. RCMS provides fleet-level visibility across hundreds of sites from a single dashboard.

Environmental and Utility Monitoring

Water quality sensors, weather stations, and utility meters frequently use RS-485 Modbus RTU to report data. The R1511e collects this data and forwards it over cellular to central monitoring platforms. The eSIM supports profile rotation, which is useful for long-term deployments where roaming agreements or tariffs need updating without a site visit.

Smart City Infrastructure

Traffic controllers, street lighting management systems, and public Wi-Fi backhaul all benefit from compact cellular routers with serial and Ethernet connectivity. The R1511e’s small footprint (31.5 x 91.5 x 91.5 mm) and DIN rail mounting make it suitable for installation in roadside cabinets and distribution boards. The embedded eSIM supports global band coverage for cross-border smart city projects.

Cellular Failover for Fixed-Line SCADA

Industrial SCADA systems running over fixed-line broadband or MPLS need a reliable backup path. The R1511e sits alongside the primary router and activates automatically when the primary link fails. RobustVPN provides a consistent fixed IP address regardless of which eSIM profile is active, so the SCADA host always reaches the device at the same address.

Frequently Asked Questions

What is an eSIM and how does it work on the R1511e?

An eSIM (embedded SIM) is a SIM chip soldered directly into the router rather than a removable plastic card. The R1511e uses an MFF2 eSIM that is GSMA SGP.22 compliant. Operator profiles are downloaded, activated, and switched remotely over the air using RCMS cloud management. The R1511e can hold up to 6 profiles simultaneously, allowing you to change operators or tariffs without a site visit. If a profile activation fails, the router rolls back automatically to the last working profile. For a full explanation, see our eSIM routers guide.

Does the R1511e support VPN?

Yes. The R1511e runs IPsec, OpenVPN, GRE, and WireGuard VPN tunnels natively on RobustOS. RobustVPN, part of the RCMS platform, provides a fixed IP address on any active eSIM profile – this is particularly useful for CCTV remote access, SCADA polling, and secure M2M communications where the host system needs a consistent IP to reach the device. See our guide to VPN on cellular routers for more detail.

What is RCMS and does it come with the R1511e?

RCMS (Robustel Cloud Manager Service) is a cloud-based platform for remote monitoring, configuration, and management of Robustel devices. It includes RobustLink for device management, RobustVPN for fixed IP address provisioning, and an Operations Console for fleet-level visibility. RCMS access is included with the R1511e at no additional charge. You can create a free account at rcms-cloud.robustel.net and begin managing devices immediately after registration.

What is the difference between the RS-232 and RS-485 variants?

The serial port interface is hardware-configured at the factory. The R1511e-4L-A35GL-A has an RS-232 port, suitable for direct point-to-point connections to PLCs, terminals, and modems. The R1511e-4L-A35GL-B has an RS-485 port, which supports multi-drop bus wiring and is used for Modbus RTU networks connecting multiple field devices on a single cable. Both variants are otherwise identical in specification. If you are unsure which interface your equipment uses, contact our UK-based technical support team on 0300 124 6181.

What is the operating temperature of the R1511e?

The R1511e operates from -25°C to +70°C and stores safely from -40°C to +85°C. It carries an IP30 ingress protection rating, meaning it is suited for installation inside enclosures or cabinets rather than direct outdoor exposure. For outdoor deployments the router should be housed in a weatherproof enclosure rated to the installation environment.

Does the R1511e need a fixed IP SIM card?

Not necessarily. RobustVPN, included in RCMS, provides a fixed IP address on any active eSIM profile – including standard dynamic-IP roaming profiles. This is different from a traditional fixed IP SIM, where the fixed IP is assigned at the network level. However, if your deployment requires a static IP assigned by the mobile network rather than via a VPN, a fixed IP SIM card may still be appropriate. Our team can advise on the right approach for your use case.

Related Products and Further Reading

For deployments requiring dual SIM physical cards rather than eSIM, the Teltonika 4G router range includes industrial models with dual Nano SIM and RutOS. For antenna requirements, browse our 4G antennas for compatible external antenna options including MIMO roof and panel antennas. If your deployment requires a fixed IP address at the network level, see our fixed IP SIM cards. For wider IoT SIM connectivity options, visit our SIM connectivity page.