Link485 4G
Cellular LTE Modbus Gateway
Link485 4G provides cellular connectivity for remote Modbus installations where Wi-Fi or Ethernet isn't available. Built-in LTE modem with global band support, SIM management, VPN tunneling, and failover capabilities make it perfect for utilities, water, and distributed infrastructure.
Key Features
4G LTE Connectivity
Built-in 4G modem with 2G GPRS fallback. Global LTE bands (Cat-1, Cat-M1, NB-IoT) with automatic network selection.
SD Card Data Storage
Local data logging with SD card slot. Store Modbus data offline and sync to cloud when connection is available.
1x Modbus RTU Interface
Connect RS-485 Modbus devices with support for baud rates from 1200 to 115200 bps and up to 32 slave devices.
Real-Time Clock (RTC)
Built-in RTC for accurate timestamping, scheduled operations, and data logging even without network connectivity.
30A High-Power Relay
Control heavy equipment with a single 30A relay output. Perfect for pump control, generator starting, and high-load switching.
Wi-Fi + BLE Radios
Built-in Wi-Fi (2.4 GHz) for local access and BLE for mobile app configuration and diagnostics without network access.
Single SIM Slot
Standard mini-SIM card slot compatible with all major carriers. Includes data plan option or bring your own SIM.
Secure VPN Tunneling
Built-in IPsec and OpenVPN support for secure communication with corporate networks and cloud platforms.
Technical Specifications
Cellular
| Technology | 4G LTE Cat-1 / Cat-M1 / NB-IoT |
| Fallback | 2G GPRS automatic |
| Bands | Global (B1/3/5/7/8/20/28) |
| SIM | 1x mini-SIM slot |
| Antenna | External, SMA connector |
Modbus & I/O
| Modbus | 1x RTU (RS-485) |
| Baud Rate | 1200 - 115200 bps |
| Relay | 1x 30A (NO/NC) |
| Relay Rating | 250V AC / 30V DC |
| Isolation | 2500V optical |
Storage & Timing
| SD Card | Up to 32GB (FAT32) |
| RTC | Battery-backed real-time clock |
| Time Sync | NTP, GPS (optional) |
Wireless
| WiFi | 1x 802.11 b/g/n 2.4GHz |
| BLE | 1x Bluetooth Low Energy |
| Use Case | Local config, diagnostics |
Connectivity
| VPN | IPsec, OpenVPN, WireGuard |
| Protocols | Modbus TCP, MQTT, HTTP |
| Firewall | Built-in NAT, port forwarding |
Power & Physical
| Input Voltage | 12-48V DC (wide range) |
| Operating Temp | -40°C to +75°C |
| Mounting | DIN rail or wall mount |
| Enclosure | IP40 (IP65 optional) |
Ideal Applications
Water & Wastewater
Remote pump stations, water tanks, treatment plants - anywhere cellular coverage exists.
Power Distribution
Remote substations, grid monitoring, distributed energy resources (DER) communication.
Agriculture
Remote irrigation systems, weather stations, soil moisture sensors across large farm areas.
Construction Sites
Temporary installations, equipment monitoring, and environmental sensors at construction sites.
Frequently Asked Questions
Link485 4G has a single mini-SIM card slot. You can use any carrier SIM (Airtel, Jio, Vi, BSNL) - both prepaid and postpaid work. You need to purchase your own SIM card and arrange a data plan with your telecom provider. The device supports standard mini-SIM cards.
Typical data consumption is 20-100 MB/month depending on polling frequency and number of Modbus devices. For example, polling 10 devices every 60 seconds uses approximately 50 MB/month. Plan your data requirements accordingly when purchasing a SIM card from your telecom provider.
Yes! Link485 4G works with both prepaid and postpaid SIMs from all Indian carriers. We recommend postpaid for critical applications to avoid service interruptions. The device can send SMS alerts when SIM balance is low.
Yes! Static IP is available from most carriers for enterprise connections. Alternatively, you can use dynamic DNS or configure VPN for remote access without static IP. Link485 Cloud provides remote access without needing static IP or port forwarding.
Link485 4G has industrial-grade modem with excellent sensitivity. It works with 2G/3G/4G and automatically selects best available network. External antenna option available for areas with very weak signal. Dual SIM allows automatic failover to backup carrier.
