PLC200

PLC200 · Browser-native automation · DIN-rail controller

PLC200 – Programmable Logic Controller with Built-in Web SCADA

PLC · Web HMI / SCADA · Data Logger · Historian · RTU · Modbus Gateway — in one compact DIN-rail device.

PLC200 is a programmable logic controller (PLC) for industrial automation, combining rich built-in I/O, Web HMI / Web SCADA, an autonomous Data Logger, a local Historian, RTU functions, a Modbus Gateway and service diagnostics in one DIN-rail device.

PLC200 industrial controller with built-in Web SCADA
Processor32 bit / 240 MHz
Power supply24 VDC or PoE
CommunicationLAN, WiFi, RS485
MountingDIN TS35 x 7.5
Local first. Remote when needed. PLC200 operates autonomously on site as a local PLC / RTU, collects data from its own inputs and Modbus devices, and can provide remote monitoring through Web HMI, a dedicated portal or an external SCADA system.

One device — several roles

PLC200 can simultaneously provide control, visualization, data acquisition, local history and upstream integration.

PLClocal logic and PID control
Web HMIoperator panels through a browser
Data Loggerdata acquisition and local logging
HistorianSQLite archive, charts and CSV
RTU / Remote Siteautonomous remote sites
Modbus Gateway / Web Tunnelmaster/slave integration and centralized access

The PLC200 philosophy — a different approach from the classic PLC

PLC200 is not intended to be a smaller copy of a large PLC system. The goal is to build, configure, operate and service a small or medium industrial site with one DIN-rail device and a standard Web browser — without a separate heavy engineering environment.

Everything important stays localPLC logic, PID, Web HMI, Data Logger, Historian and diagnostics run directly at the site.
Browser-native engineeringConfiguration, FX logic, PID, Modbus, operator panels, archives, users, updates and diagnostics are handled directly through a browser.
Integration without unnecessary complexityModbus RTU/TCP covers field devices and external SCADA integration, while Web Tunnel handles remote access when required.

Backup / Restore — fast recovery and service

The configuration can be read from the PLC, a local file or the SD card, saved as a backup and loaded again when required. The Web interface also keeps a separate working version, while panel files, images and service backups can be stored on the SD card. Recovery therefore does not depend on proprietary engineering software.

Project documentation generation: PLC200 offers an option to automatically generate project documentation, making project handover, technical maintenance and subsequent changes easier.

Configuration Backup / RestoreRead and write configuration from the device, a local file or the SD card.
Original + work copyBackup of the originally read state plus a separate current work version for safe editing.
Panels and project filesHMI panel files, backgrounds and images are stored separately and can be backed up or transferred.
Hardware / calibration backupThe SD backup directory can contain configuration, hardware and calibration backup files.

Web Tunnel – remote access without a static IP or open inbound ports

PLC200 can establish an outbound connection to a central portal running on Windows or FreeBSD. The remote site does not require a static public IP address, port forwarding or open inbound ports on the router.

Through the tunnel, the portal can provide both Web access to the built-in Web HMI / Web SCADA interface of each controller and Modbus TCP access. A central SCADA system can therefore communicate through the portal with multiple PLC200 controllers installed at different remote sites.

Each PLC200 remains an autonomous local PLC / RTU — control, Web HMI and local data logging continue to operate on site independently of the portal connection.

Remote sitePLC200 / RTU with local control
Outbound Web Tunnelno static IP and no port forwarding
Windows / FreeBSD Portalcentralized access to multiple sites
Web HMI / SCADA / Modbus TCPoperator and SCADA access
No static public IP
No inbound ports
Web HMI through portal
Modbus TCP through portal
Multiple sites to one SCADA

PLC with Web SCADA in one DIN-rail controller

PLC200 is designed for real-world sites where a standard PLC is not enough, while a separate SCADA system is too heavy in cost, maintenance and infrastructure.

Web HMI and visualization

Built-in Web HMI / Web SCADA interface for operator panels, live values, operating modes, alarms and service screens.

HMI without a dedicated panel

A tablet, Panel PC or industrial display with a modern Web browser can operate as the local HMI — without a separate SCADA computer.

Data Logger and historian

Autonomous industrial data logger with microSD, RTC/NTP, daily SQLite archives, trends, charts, tables and CSV export.

Real process control

FX formulas, PID controllers, manual/automatic mode, Modbus RTU/TCP, email notifications, built-in NTP and specialized calculation functions.

Portal and SCADA Modbus access: a Web Tunnel connection to a central Windows or FreeBSD portal can provide direct access to the Web HMI / Web SCADA interface of each controller and organize Modbus TCP access from a central SCADA system to multiple remote sites.
Browser-native engineering Configuration, FX logic, PID, operator panels, archives, users, updates and diagnostics can be handled directly through a standard browser.
Local historian Daily SQLite archives, charts and tables in the Web interface, CSV export and direct download of standard database files for external analysis.
PLC + Gateway Simultaneous Modbus master operation toward field devices and Modbus slave access for SCADA/HMI — combining Data Acquisition (DAQ), local logic and upstream integration.
Domain-specific algorithms Built-in functions for API Table 54, alcoholometry and LiFePO4 analytics extend standard PLC logic for specialized applications.

High integration — fewer separate modules

PLC200 combines measurement, control, communications, archiving and Web SCADA in one DIN-rail device, with up to 500 FX positions for formulas and virtual variables. Its rich built-in I/O can reduce the need for separate expansion modules in small and medium-sized installations.

8×Pt100 / Pt1000
24-bit, 3-wire RTD
8×differential AI
0/4–20 mA, 24-bit
8×DI 10–28 V
EN 61131-2
8×DO 10–28 V
up to 0.7 A/channel
4× FDITTL / HTL, isolated
up to 290 kHz
2×AO 0/4–20 mA
0–5 / 0–10 V
2×push-pull PWM
up to 100 kHz
2×RS485 Modbus RTU
built-in 120 Ω termination
LAN + Wi‑FiModbus TCP
Web SCADA
PoE / 24 VDCtwo power
options
32 GBmicroSD
local archive
5 / 12 / 24 Visolated process power
for field sensors

Precision measurement: 8× 24-bit differential AI and 8× 24-bit Pt100/Pt1000 inputs. High-speed inputs: 4× galvanically isolated FDI with TTL/HTL logic and individual 16 Hz / 6 kHz / 290 kHz hardware filtering. Industrial installation: 2× RS485 ports with built-in 120 Ω termination and protected digital outputs with diagnostics.

Custom I/O by project: For series production or specialized applications, PLC200 can be supplied with a customized mix of analog, temperature, digital and high-speed inputs/outputs. Conditions, the minimum agreed quantity and one-time engineering costs are determined according to the specific project.

PLC200 industrial automation applications

Pump stations and water supply

Level, pressure, flow, pumps, protection signals, counters, archives and alarm notifications.

Boiler rooms and HVAC

Temperatures, valves, PID control, operating modes, graphic panels and tuning history.

Photovoltaics and energy

Modbus communication with power meters, inverters, generators and other energy devices.

RTU and remote sites

Local autonomy, Data Acquisition, Web HMI, alarms, archives and remote maintenance without permanent on-site presence.

Meteorological and environmental monitoring

Temperature, humidity, atmospheric pressure, wind, rainfall, solar radiation, PM2.5/PM10 and other parameters from Modbus/RS485 sensors.

Hydrology and water facilities

Level, water quality and other measurements for reservoirs, canals, boreholes and water infrastructure, with local archiving and remote access.

PLC200 specifications and built-in I/O

FeaturePLC200
Processor32 bit / 240 MHz
Power supply24 VDC or PoE (IEEE 802.3af)
Communication / GatewayLAN, WiFi 2.4 GHz, 2× RS485 with built-in 120 Ω termination, Modbus RTU / Modbus TCP, Modbus master and slave operation
Network servicesDHCP Client & DHCP Server — automatic IP configuration for the controller and assignment of IP settings to devices on the local network
Inputs8× 24-bit Pt100/Pt1000 TI, 8× 24-bit differential AI, 8× DI, 4× isolated FDI up to 290 kHz (TTL/HTL), up to 100 remote RI
Outputs8× DO, 2× AO, 2× push-pull PO/PWM up to 100 kHz
Controlup to 500 FX positions for formulas/variables, PID, manual/automatic mode, specialized technological functions including API 54
Data Logger / HistorianmicroSD, RTC/NTP, daily SQLite archives, trends, tables, charts and CSV export
HMI / SCADAWeb HMI / Web SCADA through a standard browser — PC, tablet, Panel PC or industrial display
Project documentationOption to automatically generate project documentation
MountingDIN rail TS35 x 7.5
Controller, operator interface, archive and service diagnostics — without a separate computer.
Specialized embedded functions: in addition to standard PLC logic, PLC200 can use ready-made technological calculations such as temperature correction of liquid-product volume and density according to API Table 54, alcoholometric calculations from density and temperature, and LiFePO4 battery SOC and internal-resistance estimation.
Web panels and synoptics Built-in editor for operator panels with live values, command buttons, trends, bargraphs, PID controls and fullscreen operation.
Modbus and role-based access Modbus master and slave operation over TCP, RTU and RTU-over-TCP, with user roles, browser sessions and MAC/IP access restrictions.
Archives and service tools Daily SQLite archives on SD, charts and tables, CSV export, debug/communication logs and stored system logs from recent starts.
PID and AI assistance PID AutoTune, SoftStart, anti-windup and bumpless MANUAL/AUTO transfer, plus AI-assisted configuration, panel generation and diagnostics.
Autonomy and integration Core PLC control, IO, FX, PID, the Web interface and communications continue to operate without an SD card. PLC200 can simultaneously collect data as a Modbus master and expose selected values to an external SCADA system as a Modbus slave over TCP, RTU or RTU-over-TCP.
History, Backup / Restore and service Daily archives are stored as standard SQLite databases with charts, tables and CSV export. Configuration can be backed up and restored from a file or SD card; the system can retain the current and two previous system logs, while the Web interface and firmware can be updated independently.
Controlled Web access User roles, browser sessions, protection against repeated failed login attempts and MAC/IP restrictions for controlled local and service networks.

How PLC200 works in a real installation

ConnectionSensors, pumps, valves, inverter or power meter.
ConfigurationIO, alarms, FX logic, PID loops, archiving and Modbus mapping.
Web HMISynoptic screen with values, status indicators, START/STOP, reset, alarm reason and trends — available from a tablet, Panel PC or industrial display with a browser.
OperationLocal operation through a tablet, computer or smartphone.
MaintenanceAbout, debug log, communication log, archive charts, remote update and configuration changes.

PLC200 automation solutions

PLC200 can be the core of complete solutions for specific technological tasks. The examples below combine process control, Web visualization, local archiving and remote maintenance in one platform.

TYPICAL SOLUTION 01

3-phase motor control and monitoring

PLC200-MPC can be used as a compact solution for motor control panels where automatic start/stop, energy monitoring, alarms and browser-based remote access are required.

One module for measurement, control and monitoring

The controller measures phase currents through current transformers, monitors motor load and can operate the contactor through a digital output.

Via LAN or WiFi, the operator can view live values, status, alarms and operating modes from a phone, tablet or computer — without a separate SCADA PC.

  • Current measurement on L1, L2 and L3 and power consumption monitoring.
  • Automatic motor start / stop according to logic, operating mode or alarm condition.
  • Monitoring for overload, phase loss, abnormal current and service events.
  • Web interface for local or remote access through a standard browser.
The image is a conceptual marketing diagram. Actual wiring must follow the specific control panel design, protections and electrical project.
PLC200-MPC typical solution for 3-phase motor control and monitoring through a browser
TYPICAL SOLUTION 02

Irrigation and microclimate automation

A solution for greenhouses, orchards, open-field crops and pump stations in which PLC200 manages irrigation, monitors microclimate conditions, stores process data and provides remote access.

Precise irrigation, fertigation and monitoring

The controller can operate pumps, solenoid valves and variable-frequency drives. PID control can maintain the required pressure in drip irrigation or pivot systems.

RTD temperature sensors for soil and air, as well as analog sensors for humidity, EC/pH and pressure, can be connected directly. Weather stations and other field devices can be integrated through Modbus.

  • Automatic control of irrigation zones, pumps and valves.
  • VFD and dosing pump control for water and fertilizer delivery.
  • Web SCADA monitoring and control from a computer, tablet or smartphone.
  • SD-card archive of temperature, humidity, water consumption and other process parameters.
  • Email notification for alarm conditions such as low pressure or critical temperature.
MeasurementAir and soil temperature, humidity, EC/pH, pressure and flow.
ControlPumps, valves, variable-frequency drives and dosing pumps.
CommunicationLAN, Wi-Fi and Modbus to weather stations and field devices.
OperatorLive values, charts, alarms and commands through a standard browser.
HistoryLocal SD-card archive for subsequent analysis of irrigation processes.
TYPICAL SOLUTION 03

Meteorological and environmental monitoring

PLC200 can operate as a local data concentrator and Web SCADA node for meteorological, agricultural, hydrological and photovoltaic sites using Modbus/RS485 sensors.

Sensors, local archive and remote access in one system

Field instruments for temperature, humidity, atmospheric pressure, wind speed and direction, rainfall, solar radiation, PV module temperature, PM2.5/PM10, level and other parameters can be connected to PLC200.

Values are read over Modbus RTU/RS485, displayed through Web SCADA, archived locally and can be exposed to an external SCADA system or a dedicated portal over Modbus TCP.

  • Integration of Modbus/RS485 meteorological and environmental sensors.
  • Unified Web screen for live values, alarms and trends.
  • Local SD-card archive with time synchronized by the built-in NTP function.
  • Email notification for exceeded limits or lost communication.
  • Direct access through a dedicated portal or SCADA Modbus TCP to multiple remote sites.
MeteorologyTemperature, humidity, pressure, wind, rainfall and solar radiation.
PhotovoltaicsGlobal/plane-of-array irradiance, module temperature and local weather conditions.
EnvironmentPM2.5/PM10, noise, gas and other specialized sensors according to the project.
Agriculture and soilSoil moisture, temperature, pH/EC and irrigation or microclimate parameters.
Water facilitiesLevel and water-quality parameters through compatible field sensors.

PLC200 series

PLC200-AI

Compact variant for analog and temperature measurements.

PLC200-MPC

For photovoltaics, generators, micro power plants, pump stations and energy systems.

PM200

Smart power meter with Web SCADA, built-in database, LAN/WiFi and microSD archives.

Do you have an automation project?
Contact us to select the appropriate model from the PLC200 series.
Send inquiry www.unisyst.bg

Frequently asked questions

What is Web SCADA in PLC200?

The controller hosts a browser interface with operator panels, process graphics, live values, commands, alarms and charts. Operators use it on the local network; remote access is arranged for the installation when needed.

Does PLC200 require a separate HMI or SCADA PC?

For local operation, a tablet, panel PC or display with a modern browser can show the PLC200 interface. An external SCADA system can still be connected for larger installations.

Can PLC200 operate without Internet access?

Yes. Local PLC logic, I/O, PID control and the Web interface run at the site without an Internet connection. Logging uses a microSD card where process history is required.

Can PLC200 operate as both Modbus master and slave?

Yes. PLC200 can poll field equipment as a Modbus master and make values available to an external SCADA/HMI as a Modbus slave over supported RTU/TCP interfaces. Configuration depends on the system design and register map.

How does PLC200 log and store process data?

With microSD and RTC/NTP timekeeping, PLC200 stores daily SQLite archives. Operators can view charts and tables in the Web interface and export CSV or download standard DB files.