The HD81 series is a digital controller and display unit designed for monitoring and controlling environmental parameters; it is available in various models for measuring temperature, humidity, and carbon dioxide (CO₂). Equipped with an LCD display, relay outputs, and an RS485 communication interface (supporting the MODBUS/RTU protocol), the device is suitable for integration into control and monitoring systems.
A key feature of the HD81 controller is its ability to connect to monitoring and automation systems via an RS485 port. The device’s serial communication supports the MODBUS/RTU protocol, with data transmission speeds adjustable between 2,400 and 57,600 bps.
The HD81 controller features a 2-line, 16-character LCD display that shows measured values. This allows for the quick viewing of environmental parameters and the device's operational status without requiring a connection to a monitoring system. Description Specification
HD81 Product Series
Temperature, Humidity, Carbon Dioxide Measurable Parameters
24VDC ±10% Power Supply
RS485 Communication Interface
MODBUS/RTU Protocol
2400 – 57600 Bit/s Communication Speed
None/Odd/Even Parity
Max. 4 Relays Output
Normally Open Contact Type
16x2 Character LCD Display
-20 to +50°C Operating Temperature
0 to 95% Ambient Humidity
Note: Precise specifications regarding measurement ranges, the number of relays, and measurable parameters should be verified based on the specific HD81 model selected.
Applications of the HD81 Temperature and Humidity Controller
The HD81 controller is suitable for systems requiring the measurement, display, and control of environmental conditions, including: • HVAC systems • Cleanrooms • Pharmaceutical and laboratory facilities • Industrial production halls • Warehouses and cold storage • Greenhouses • Equipment and server rooms • Monitoring and BMS systems • Fan and ventilation control • Ambient pressure and differential pressure control
In projects requiring the simultaneous monitoring of multiple environmental parameters, the appropriate HD81 model enables both local data display and data transmission to a central control system.
