01RTU
Switches the lighting
The control module turns the lighting on and off by sunrise and sunset. It has its own clock with a backup battery, so the schedule holds even when the connection drops.
Open the module
Street lighting management
GridBit SLMS puts a street lighting cabinet on the network. You see voltage, current and power per phase, switch the lighting from a map and get an alarm when a branch fails.
- Control at cabinet level
- Modbus RTU modules on a DIN rail
- Keeps the schedule without a connection
- 5000+
- street lighting cabinets digitalised
- 80+
- municipalities with GridBit SLMS
- 30+
- partner companies
- 15+
- years in street lighting
The problem
Most cities cannot see their street lighting
A cabinet switches a few streets on and off, and nobody knows what happens inside it until someone reports a dark street. Cities need to see and control the network to deal with:
- 01High electricity costs
- 02Theft and losses that are hard to find
- 03Late information and slow repairs
- 04Expensive, inefficient maintenance
- 05Targets for lower emissions
How it works
From the cabinet to the screen
The system works at cabinet level. Compact modules go on the DIN rail of the existing cabinet and talk to each other over Modbus.
02MCU
Measures every phase
The network analyser reads voltage, current, power, cos φ and energy per phase. The current shows failed luminaires and loads that should not be on the line.
Open the module
03SMU
Watches the branches
The voltage detector checks up to eight outgoing branches. A tripped breaker or a blown fuse shows up as a branch without voltage, by number.
Open the module
04GWU
Connects the cabinet
The gateway reads the modules over Modbus RTU and sends the data over the mobile network. One gateway reads up to 127 devices.
Open the module
05WDT
Restarts what hangs
If the electronics stop answering after a surge or a bad supply, the watchdog module restarts them. Nobody drives to the cabinet for a reset.
Open the module06Platform
Shows it all in a browser
Map, live diagram, alarms, history and reports. No servers to buy: you open the platform on a phone, tablet or laptop.
The platform
What the operator sees
Every cabinet on one map
Plovdiv: 267 cabinets on one map. Markers show the state of each cabinet, clusters open as you zoom in and a filter narrows the map to the cabinets you need.
One click opens the cabinet
Photo, group, the schedule for the day, connection, GSM signal and active alarms. From here you switch the lighting or open the full technical view.
Remote switching asks for a PIN
Turning the lighting on or off from the platform needs a PIN code set by the administrator, so nobody switches a street by mistake.
The cabinet as a live diagram
The single-line diagram of the cabinet with live values: voltage, current and power per phase, the contactor, the breakers and the state of every outgoing branch.
Live Pulse: a virtual meter for the city
Energy for today, the week, the month and the year, the current power and a corridor of normal consumption learned from the last 14 days.
History for any period
Charts of voltage, current, power and cos φ per phase, with the state of the branches and the relay at each moment. Export to Excel.
Alarm reports with expected and measured values
Every alarm per cabinet with start, end, the expected range and the measured value, for example a phase current outside its range. Each cabinet links to the map.
A log of availability
Day by day, which cabinets reported all day, part of the day or not at all, with signal strength and mobile operator.
An AI helper inside the platform
Ask it how to configure something, or to summarise the alarms and logs in plain language.
Keep scrolling
Screens from the installation in Plovdiv. Serial numbers, coordinates and addresses are blurred.
The platform
What the operator sees
Every cabinet on one map
Plovdiv: 267 cabinets on one map. Markers show the state of each cabinet, clusters open as you zoom in and a filter narrows the map to the cabinets you need.
One click opens the cabinet
Photo, group, the schedule for the day, connection, GSM signal and active alarms. From here you switch the lighting or open the full technical view.
Remote switching asks for a PIN
Turning the lighting on or off from the platform needs a PIN code set by the administrator, so nobody switches a street by mistake.
The cabinet as a live diagram
The single-line diagram of the cabinet with live values: voltage, current and power per phase, the contactor, the breakers and the state of every outgoing branch.
Live Pulse: a virtual meter for the city
Energy for today, the week, the month and the year, the current power and a corridor of normal consumption learned from the last 14 days.
History for any period
Charts of voltage, current, power and cos φ per phase, with the state of the branches and the relay at each moment. Export to Excel.
Alarm reports with expected and measured values
Every alarm per cabinet with start, end, the expected range and the measured value, for example a phase current outside its range. Each cabinet links to the map.
A log of availability
Day by day, which cabinets reported all day, part of the day or not at all, with signal strength and mobile operator.
An AI helper inside the platform
Ask it how to configure something, or to summarise the alarms and logs in plain language.
Screens from the installation in Plovdiv. Serial numbers, coordinates and addresses are blurred.
Live Pulse
The load curve tells you what happened at night
Street lighting has a simple signature: a step up at dusk, a flat load through the night, a step down at dawn. Live Pulse learns this shape from the last 14 days and draws a corridor around it.
A line outside the corridor means something changed: lamps that failed, a branch without voltage or a load that should not be there.
- A virtual meter for the whole network: today, this week, this month, this year
- Share of the time inside the corridor, per day, week, month and year
- An alarm when the load leaves the corridor
Benefits
What you get
10 to 15 %
energy saved by optimising the schedule
20 to 30 %
lower maintenance costs
01
Failed luminaires found on time
The current of a phase drops when lamps fail. The alarm names the cabinet and the phase.
02
Unauthorised connections detected
A load that is not lighting shows in the measured current and in the load curve.
03
Faults in the supply found quickly
Missing voltage on a phase or a branch is visible at once, with the time it started.
04
The investment managed after the project
Reports and history show what the new lighting consumes and how it behaves, year after year.
In the field
Made for real cabinets
Recovers by itself
The watchdog module restarts the electronics if they hang after a surge or a bad supply.
Works without a connection
When the mobile network is down the lighting keeps its schedule. The clock of the control module has a backup battery.
No servers to buy
The platform runs in the cloud and opens in a browser on a phone, tablet or laptop.
Thousands of devices
The platform receives, checks and shows the state of thousands of devices within seconds.
One Modbus bus, room for more
The modules talk Modbus RTU and one gateway reads up to 127 devices, so a cabinet can carry more than lighting. Options for a project:
Environmental sensors
Particulate matter, CO2 or noise on the existing bus, without new cabling.
EV charging
Power is already measured, so charging points can be balanced against the load.
Door and vibration sensors
For the cabinet door and for the cable network.
Dimming modules
Lower light in the small hours for extra savings.
For whom
Who uses it
01
Municipalities
See where the lighting budget goes and what state the network is in.
02
ESCO companies and contractors
Measure the savings of a project and manage it after commissioning.
03
Maintenance companies
Drive out knowing which branch failed and which parts to take.
Projects
Dusk in more than 80 municipalities
ADD Bulgaria has worked on street lighting control for more than 15 years. GridBit is its technology brand.
- 5000+
- street lighting cabinets digitalised
- 80+
- municipalities with GridBit SLMS
- 30+
- partner companies
- 15+
- years in street lighting
Municipalities from the project map
- Balchik
- Dobrich
- Sozopol
- Pomorie
- Devnya
- Sungurlare
- Yambol
- Omurtag
- Lyubimets
- Ruse
- Dimitrovgrad
- Dryanovo
- Kardzhali
- Kirkovo
- Svishtov
- Pavlikeni
- Brezovo
- Sopot
- Plovdiv
- Hisarya
- Smolyan
- Saedinenie
- Stamboliyski
- Devin
- Pazardzhik
- Dospat
- Belovo
- Sarnitsa
- Roman
- Miziya
- Mezdra
- Vratsa
- Bansko
- Sofia
- Montana
- Dupnitsa
- Pernik
- Dragoman
Clients
What clients say
ADD Bulgaria stands out with professionalism, technical competence and correctness in projects for the modernisation of street lighting. We especially value their commitment in the field and their quick reaction to specific requirements.
The team of ADD Bulgaria reacts quickly and flexibly to different requirements and challenges.
The GridBit SLMS system has brought real benefits to the municipalities we work with.
Thanks to the innovative solutions and the support of ADD Bulgaria, the street lighting systems that were put in place work reliably and contribute to energy efficiency, safety and the modernisation of the urban environment.
Translated from Bulgarian.
Hardware in this system
GatewayGWU-54G LTE gateway for Modbus devices, with Ethernet and MQTT4G LTE Cat 1Mobile network, 2G fallbackRS485 + EthernetModbus RTU and Modbus TCP
MeterMCU-4Three-phase network analyser with Modbus RTU3P+N / 1P+NPole configurationU, I, P, cos φ, EMeasured parameters
RelayRTU-4Astronomical relay with Modbus RTU and energy saving modeSunrise and sunsetRelay schedule250 VACMax. relay voltage
InputsSMU-3Eight-channel AC voltage detector with Modbus RTU8Voltage detection inputs280 VACMaximum input voltage
WatchdogWDT-1Watchdog relay that restarts devices when Modbus communication stopsNormally openRelay contact250 VACMax. relay voltage
WatchdogWDT-4Modbus watchdog relay, fallback to photo sensor or clockNormally openRelay contact250 VACMax. relay voltage
What is GridBit SLMS?
GridBit SLMS is a street lighting management system that works at cabinet level. Modules on the DIN rail of the existing cabinet switch the lighting, measure every phase and watch the outgoing branches. A gateway sends the data over the mobile network, and the platform shows every cabinet on a map with alarms, history and reports.
Does the lighting keep its schedule when the connection drops?
Yes. The control module switches the lighting by sunrise and sunset and has its own clock with a backup battery. When the mobile network is down, the lighting keeps its schedule.
How does the system find failed luminaires and unauthorised connections?
It reads the current of every phase. The current drops when lamps fail, and a load that is not lighting shows in the measured current and in the load curve. Live Pulse learns the normal curve from the last 14 days and raises an alarm when the load leaves that corridor.
How much does street lighting management save?
The figures GridBit works with are 10 to 15 % energy saved by optimising the schedule and 20 to 30 % lower maintenance costs. The reports and the history show what the lighting consumes after the project, year after year.
Which hardware goes into a cabinet?
Five modules on the DIN rail. RTU-4 switches the lighting, MCU-4 measures voltage, current, power, cos φ and energy per phase, SMU-3 watches up to eight outgoing branches, a GWU gateway connects the cabinet and a WDT watchdog relay restarts the electronics if they hang. One gateway reads up to 127 Modbus devices.
Do we need our own servers?
No. The platform runs in the cloud and opens in a browser on a phone, tablet or laptop.
Where does the system work today?
In more than 80 municipalities in Bulgaria, with more than 5 000 street lighting cabinets digitalised. The installation in Plovdiv shows 267 cabinets on one map.
Can the cabinet carry more than lighting?
Yes. The modules share one Modbus bus, so a project can add environmental sensors for particulate matter, CO2 or noise, EV charging balanced against the load, door and vibration sensors, and dimming modules.
Ask for a street lighting proposal
Tell us how many cabinets you have and what is in them. We answer with a configuration and a quote.