LRM-UNI3
Wireless Modbus – LoRa BridgeReplace long, costly RS485 cable runs with a secure LoRa radio link. The LRM-UNI3 transparently carries Modbus RTU and other serial data between PLCs, SCADA, energy meters, inverters, VFDs and sensors — across a plant, between buildings or over kilometres of open ground.
- Bi-directional, transparent serial ↔ LoRa transmission — no protocol changes on your devices
- Point-to-point or one master to many slaves, with transparent, fixed-point and broadcast modes
- Long-range, interference-resistant LoRa with up to 22 dBm adjustable output and encrypted data
- Plug-and-play: set frequency, address, baud rate and RF power with the PC configurator
Make any Modbus link wireless
Running RS485 cable between buildings, across yards or through live plant areas is slow and expensive, and long cables pick up interference. The LRM-UNI3 turns that cable into a LoRa radio link: connect one unit to your Modbus master and another to each slave device, and serial data flows between them exactly as if they were wired.
Because the bridge is fully transparent, your PLC, SCADA or meter keeps polling with the same Modbus RTU addresses and registers — no gateway programming or protocol mapping is needed. LoRa’s spread-spectrum modulation gives long range and strong immunity to electrical noise, and the data is encrypted over the air.
Compact and DIN-rail mounted, the LRM-UNI3 fits straight into control panels and runs from any 9–28 V DC supply.
Three transmission modes
Data in on the serial port comes out unchanged on every unit with the same address and channel — ideal for simple Modbus links.
Each message is addressed to a specific unit and channel, so one master can talk selectively to many slaves.
One message reaches every unit on the channel at once — useful for time sync or group commands.
| General | |
|---|---|
| Model number | LRM-UNI3 |
| Product type | Wireless Modbus – LoRa bridge |
| Function | Bi-directional, transparent RS485 ↔ LoRa data transmission |
| Mounting | 35 mm DIN rail (panel installation) |
| Configuration | PC configuration software — no programming required |
| Wireless | |
| Technology | LoRa spread-spectrum modulation |
| Frequency band | 433 MHz / 865–868 MHz / 915 MHz (regional variants) |
| RF output power | Up to 22 dBm, software adjustable |
| Range | Up to 2km line of sight (depends on antenna, power and environment) |
| Air data rate | 0.3 – 62.5 kbps (configurable) |
| Network | Point-to-point and point-to-multipoint |
| Transmission modes | Transparent, fixed-point, broadcast |
| Security | Encrypted LoRa link |
| Antenna | SMA female connector, external antenna | Power & environment |
| Power supply | 8–28 V DC (DC jack or terminals) |
| Consumption | Max 1 W (approx. 45 mA at 12 V idle) |
| Operating temperature | -20 °C to +70 °C |
| Storage temperature | -40 °C to +85 °C |
| Humidity | 5–95% RH, non-condensing |
| Mechanical | |
| Dimensions (H × W × D) | 125 × 30 × 66 mm |
| Weight | Approx. 93 g |
Quick setup
- Configure both unitsConnect each LRM-UNI3 to a PC and set the same frequency channel, air data rate and transmission mode, plus each unit’s address. Match the serial baud rate and format to your Modbus devices (default 9600, 8N1).
- Fit the antennasScrew an antenna onto each SMA connector before powering on. Mount antennas outside metal enclosures and as high as practical for best range.
- Wire serial and powerConnect A+ / B− to the Modbus device’s RS485 terminals and supply 9–28 V DC.
- Test the linkPoll a slave from your master and watch the TX / RX LEDs. If needed, raise RF power or lower the air data rate to extend range.
Cut the cable, keep the protocol
Link devices across roads, yards and buildings without digging trenches or pulling long RS485 runs.
Existing Modbus RTU masters and slaves work unchanged — same addresses, same registers, no remapping.
LoRa spread-spectrum modulation resists interference from drives, switchgear and motors; data is encrypted.
Compact DIN-rail housing, wide 9–28 V DC input and screw terminals for quick installation.
Build out your wireless network
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Planning a wireless Modbus link?
Tell us the distance, devices and baud rate, and we’ll recommend the right frequency band, antennas and configuration for your site.
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