Project Introduction: Commercial glass greenhouses are high tech production facilities for growing vegetables or flowers, filled with equipment like screening installations, heating, cooling, and lighting. In many cases, these systems are automatically controlled by a computer to regulate and maintain proper plant growth. One of our customers aimed to develop a PC-based control system for automatically monitoring the temperature of their greenhouse.

System Requirements: Due to the fragile nature of growing plants within a greenhouse, this customer had strict requirements for the implementation of their automated system, which included the following:

• The temperature and humidity of the greenhouse should be recorded and allow automatic adjustments.
• The system should allow remote monitoring and control through the Internet.
• Any failure of the air-conditioner needs to be immediately reported to the administrator.
• Surges from outside should be avoided in order to prevent the controller from malfunctioning.
• The greenhouse was far from the control station, requiring highly reliable products.

Project Implementation:

ADAM-4017: 8-channel Analog Input Module

ADAM-4015: 16-channel Isolated Digital Input Module with Modbus

ADAM-4056S: 12-channel Sink Type Isolated Digital Output Module with Modbus

ADAM-4052: 8-channel Isolated Digital Input Module

ADAM-4571L: 1-port RS-232 Serial Device Sever

ADAM-4068: 8-channel Relay Output Module with Modbus

TPC-1570H: 15" XGA TFT LCD Pentium M / Celeron M Touch Panel Computer

Software: ADAMview

System Description: All temperature and humidity data is sent to the ADAM-4017, while the signals monitoring the air-conditioner are sent to ADAM-4501. The temperature of air-conditioner is adjusted and controlled by ADAM-4068 and ADAM-4056S. Communications are supported by RS-485. If the PC does not support Ethernet, then the conversion could be supported by ADAM-4520. The program can be implemented manually or automatically, and any alarm event record can be searched and viewed on the PC screen. The temperature and humidity can be configured and adjusted on a timer according to season, weather, etc. The variation of temperature and humidity is shown and analyzed by the curve chart. The entire system can be remotely controlled through the Internet.

Conclusion: This system can remotely monitor and manage the temperature and humidity within the greenhouse through the Internet, providing a more accurate, efficient and reliable system than constant physical monitoring. Due to the distance from the control room, the rigorous monitoring requirements and the demanding physical environment of the greenhouse, Advantech's ADAM series was the ideal solution