INDUSTRY & GRID / SCADA INTEGRATION
Bring legacy serial and remote IO into modern SCADA
The short answer
A Milesight UC100 is £38.90 ex VAT and polls an existing Modbus RTU meter or PLC, then backhauls the registers over LoRaWAN. The UC300 with digital and analogue IO is £104.74. This is wireless remote telemetry, not a wired Modbus TCP I/O rack in a panel.
Last reviewed by Indiott (PSI Technologies Ltd)
Your SCADA wants clean Modbus TCP, but the plant is full of serial PLCs, energy meters and RTUs still speaking Modbus RTU or raw serial over RS-232/485, and half the assets you need to see are at remote sites with no PLC, no Ethernet and sometimes no mains. Stringing copper back to a marshalling cabinet, or rip-and-replacing perfectly good serial devices, is slow and expensive. What you need is reliable serial-to-Ethernet and cellular gateways, plus drop-in remote IO where there simply is no controller.
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The difference
Your SCADA wants clean Modbus TCP, but the plant is full of serial PLCs, energy meters and RTUs still speaking Modbus RTU or raw serial over RS-232/485, and half the assets you need to see are at remote sites with no PLC, no Ethernet and sometimes no mains. Stringing copper back to a marshalling cabinet, or rip-and-replacing perfectly good serial devices, is slow and expensive. What you need is reliable serial-to-Ethernet and cellular gateways, plus drop-in remote IO where there simply is no controller.
What you get
Legacy serial PLCs, meters and RTUs presented to SCADA as clean Modbus TCP via serial gateways, no rewiring, no device replacement
Remote and unmanned sites brought online over 4G/5G with cellular serial gateways, so a borehole or kiosk reports without a copper run
Real IO where there is no PLC: remote IO controllers read digital and analogue inputs and drive relay or valve outputs, locally and on a schedule
Edge logic that keeps working through a comms outage and reports cleanly to SCADA, BMS or a dashboard when the link returns
What this covers
Wireless Modbus RTU acquisition over LoRaWAN, for assets where running cable is not viable — a remote pumping station, a rooftop plant skid, a meter in a locked riser, a field cabinet. The controller reads the RS485 registers and carries them back over LoRaWAN.
What it does not
A wired Modbus TCP I/O rack sitting on the same network as your SCADA master. If the asset already has Ethernet to it, this is the wrong architecture — you want a wired remote I/O rack, and LoRaWAN would only add latency and a radio hop for no benefit.
We also stock wired serial and Modbus gateways for the cabled case. Tell us which side of that line you are on and we will quote the right one.
The full stack, applied here
Every Indiott build runs all five layers as one accountable system. Follow a single modbus poll from the sensor that catches it to the report that proves it.
Remote IO controllers read dry contacts, 4-20 mA sensors and pulse meters at sites that never had instrumentation reach a PLC or Ethernet.
Hands a raw reading to CONNECT ↓
The core: serial gateways present legacy RS-232/485 devices to SCADA as clean Modbus TCP, and cellular serial gateways reach sites with no fixed line.
Hands a mapped register to SECURE ↓
The core: every serial-to-Ethernet and cellular gateway sits in IEC 62443 zones and conduits, so a remote borehole link never opens an uncontrolled path into control.
Hands a trusted stream to CONTROL ↓
Remote IO controllers drive relay and valve outputs on local logic or a schedule, so a pump switches and an alarm latches on-site even when the central SCADA link is down.
Hands an action and proof to MANAGE ↓
Everything lands in SCADA, BMS or a dashboard as standard Modbus or MQTT, with DNP3 where utility masters need it, so a dropped RTU is an alert not a silent gap.
The loop is closed ✓
How teams start
You do not boil the ocean. Nearly every rollout runs the same four moves, and you own a working, evidenced result at the end of the first one.
We walk the sites, list the assets and pin the one constraint that matters, then agree what a good result looks like before a single sensor is bought.
A focused set of sensors goes onto one site or asset group, live on our telemetry and dashboards, wired to the people who need the alert.
We tune thresholds, kill false positives, confirm the integration into your SCADA, BMS or CAFM, and write the standard design down so it repeats.
The proven design rolls out across the estate, reusing the same hardware standards and data models so every site reads the same way.
Milesight UC100 IoT Controller
£38.90 ex VAT
Milesight UC300 IoT Controller
£104.74 ex VAT
Milesight UC501 IoT Controller
£119.71 ex VAT
Urban.io On/Off Sensor
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Urban.io Process Loop Sensor
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ATOP MB5901 Rugged Serial to Ethernet Modbus Gateway
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ATOP SE5901 Rugged Serial to Ethernet Device Server
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ATOP SE5901B Cellular Serial to Ethernet Device Server
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Modbus remote IO costs between £38.90 and £119.71 ex VAT in the UK. Indiott published prices, September 2026. Delivery is charged by weight; VAT is added at checkout.
| Model | Key specification | Price ex VAT | Availability |
|---|---|---|---|
| Milesight UC100 IoT Controller UC100 | Modbus capacity over RS485: Up to 32 Modbus registers / 32 Modbus RTU devices on 1 × RS485 | £38.90 – £43.39Price range: £38.90 through £43.39 ex VAT (£46.68 – £52.07 inc. VAT) | In stock, UK · dispatched within 14 working days |
| Milesight UC300 IoT Controller UC300 | I/O interface count: 4 × DI + 2 × DO relay, 2 × 4~20 mA + 2 × 0~10 V analogue, 2 × PT100 RTD, 1 × RS232 + 1 × RS485 | £104.74 – £157.12Price range: £104.74 through £157.12 ex VAT (£125.69 – £188.54 inc. VAT) | In stock, UK · dispatched within 14 working days |
| Milesight UC501 IoT Controller UC501 | Power supply: 2 × 2550 mAh rechargeable ICR18650 batteries with embedded solar panel (6 V, 1.7 W) | £119.71 – £128.69Price range: £119.71 through £128.69 ex VAT (£143.65 – £154.43 inc. VAT) | In stock, UK · dispatched within 14 working days |
| Urban.io On/Off Sensor | — | Price on request | Quote only |
| Urban.io Process Loop Sensor | — | Price on request | Quote only |
| ATOP MB5901 Rugged Serial to Ethernet Modbus Gateway MB5901 | Ethernet connector ports: RJ45 x 2 (dual-port, with 802.1D-2004 RSTP redundancy) | Price on request | Quote only |
| ATOP SE5901 Rugged Serial to Ethernet Device Server SE5901 | Ethernet Ports and Redundancy: 2 × 10/100BASE-T(X) RJ45 with RSTP, -40°C to +85°C | Price on request | Quote only |
| ATOP SE5901B Cellular Serial to Ethernet Device Server SE5901B | Cellular: 4G LTE Cat 4, single SIM, with VPN router functions | Price on request | Quote only |
Brands in this kit: Milesight · Urban.io · Atop Technologies
Why Indiott
We pick the best of each brand for the layer and the environment, not one vendor catalogue. Milesight, AquaIoT, Atop, Browan, SpecSens and Urban.io, chosen on merit.
Sensing, connectivity, OT security, control and the dashboard come from one accountable team, so there is no finger-pointing when something needs to talk to something else.
UK-based engineers scope the site, quote the kit and stand behind it, with compliance mapped to the regimes your auditors actually cite.
Prices are shown where we can, quoted fast where we cannot, and you get a straight answer and a bill of materials within one working day.
DEPLOYED IN THE FIELD
| Standard | What it requires |
|---|---|
| Modbus TCP / RTU | the de-facto industrial protocol; gateways convert RTU and raw serial to TCP and back so legacy devices and modern SCADA speak the same language without bespoke drivers |
| DNP3 | supported where utility RTUs and SCADA masters require it, so meters and outstations integrate to grid and water control systems on their native protocol |
| IEC 62443 | segment serial-to-Ethernet and cellular gateways into defined zones and conduits so remote-site connectivity does not open an uncontrolled path into the control network |
A serial-to-Ethernet or Modbus gateway is typically a couple of hundred pounds per device, a cellular serial gateway for a remote site a few hundred plus the data SIM, and a remote IO controller with the IO mix you need usually well under a few hundred pounds depending on input and output count. A multi-site SCADA integration is quoted against the number of serial devices, remote sites and IO points. Send us your device list and the exact figures come back within one working day.
The UC300 IoT controller (£104.74 ex VAT) offers digital inputs and outputs, analogue 4-20mA and voltage inputs, and a Modbus RTU master to poll meters and instruments. The UC501 (£119.71) and UC502 (£122.70) extend the input mix. So one node reads status, level, flow or pressure and can also switch an output, all reported wirelessly.
The gateway forwards readings north by Modbus TCP or MQTT, so your SCADA or telemetry master polls or subscribes exactly as it would a wired RTU. The remote IO appears as tags in the existing system rather than a separate portal, which keeps operators on one HMI across wired and wireless outstations.
Yes. The controllers provide digital and relay outputs, and the UC511 solenoid valve controller (£119.71 ex VAT) is purpose-built to drive latching solenoid valves in the field, for irrigation, water and drainage. So you both read status and issue commands over the same wireless link, within the safety design of the process.
The UC300 acts as a Modbus RTU master, polling existing serial meters and instruments and transmitting their registers over LoRaWAN. For pure serial-to-Ethernet conversion on a wired network, ATOP serial device gateways bridge RS-232/485 to Modbus TCP. Either way, legacy field devices are brought into SCADA without replacing them.
LoRaWAN is low power and licence-free, so battery or solar outstations run for years and there is no per-site SIM cost across a private network. One gateway covers several kilometres, which suits clusters of pumps, chambers or tanks. Cellular still suits a lone, distant site, but a group of outstations is cheaper and simpler on private LoRaWAN.
LoRaWAN is designed for long-range, low-rate telemetry with acknowledged uplinks and configurable retries, which suits status and metering that update on a schedule rather than millisecond control. Critical local control stays in the field device, and the wireless link carries the telemetry and setpoints back to SCADA, so a brief radio gap does not stop the process.
No — this is wireless Modbus RTU acquisition over LoRaWAN, for assets where running cable is not viable: a remote pumping station, a rooftop skid, a meter in a locked riser. The controller reads the RS485 registers and carries them back over radio. If the asset already has Ethernet to it, you want a wired Modbus TCP I/O rack instead, and LoRaWAN would only add a radio hop for no benefit. We stock wired serial and Modbus gateways for that case.
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Tell us the site, the assets and the constraint. You get a bill of materials and a straight answer within one working day.
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