A substation monitoring system is only as good as its data path. Sensors are distributed across the switchyard, the switchgear room and the cable tunnels; they speak different physical interfaces; and the control room needs the data on a network that is not always convenient to reach. The IoT gateway is the device that makes the sensor network coherent. This article explains the HUWOR IoT gateway (model HMJ1020-WJM485).
One gateway, many sensors
The HMJ1020-WJM485 is a multifunctional relay device that supports multiple communication methods, including LoRa, RS485, Ethernet and fibre-optic connections. This means a single gateway can collect data from:
- Wired sensors on switchgear panels and GIS compartments (RS485)
- Wireless sensors in switchrooms and cable tunnels (LoRa)
- Distant points connected over the site network (Ethernet, fibre)
Instead of running separate wiring and separate software for each sensor type, the project installs one gateway per zone and connects it to the control network.
Data acquisition, edge computing and local storage
The gateway integrates three functions that used to require three separate devices:
- Data acquisition – reading the measured values from the connected sensors on their native interfaces and protocols
- Edge computing – applying local logic such as threshold checks, trend windows and alarm rules at the gateway, so the control centre receives events rather than raw floods of data
- Local data storage – keeping a buffer of the measurements, so the data survives a communication outage and can be retrieved when the link is restored
This combination is what makes a monitoring system robust: when the network link fails, the gateway keeps recording, and no measurements are lost.
Specifications and installation
According to the published specification, the rated voltage and frequency of the HMJ1020-WJM485 is 100-240 V AC, 50/60 Hz, measured under the reference conditions stated in the datasheet. The gateway is designed for indoor monitoring environments – substation control rooms, switchgear rooms and auxiliary buildings – where it is mounted in the cabinet and powered from the station supply.
The gateway in the HUWOR architecture
In a typical project, the architecture has three layers:
- Field sensors – PD sensors, temperature monitors, gas sensors, arrester monitors
- IoT gateways – aggregating each zone, applying edge logic, storing data locally
- Platform – the control-centre software that displays trends, raises alarms and produces reports
The HMJ1020-WJM485 sits in the middle layer, converting the sensor protocols to the platform format and keeping the data flowing through communication outages. Because the gateway accepts several communication modes, a project can start with wired sensors and add wireless sensors later without changing the gateway.
Summary
The IoT gateway is what turns a collection of sensors into a monitoring system. The HMJ1020-WJM485 aggregates LoRa, RS485, Ethernet and fibre connections, applies edge computing, stores data locally, and runs on 100-240 V AC station supply. HUWOR supplies the gateway with OEM/ODM support. Contact the HUWOR sales team for a gateway plan and system architecture.