Application of Advantech Products in Water Quality Monitoring of Fish Farms

Fish farm water quality monitoring
Overview
Owners of fish and shrimp farms and fisheries need to monitor their fish farms to maintain good water quality. A well-known university in Malaysia has launched a research project to develop new, more effective systems to monitor and control the water quality of fish farms and fisheries. They developed a working system using Advantech ADAM Series modules.





·System Requirements
There are three key factors that affect the quality of fish farm water: dissolved oxygen in the water, the acidity of the water, and the temperature of the water. In this application, a suitable sensor is used to collect the data obtained by measuring these three parameters and then send it to a control computer in a laboratory 30 meters away. The software in the computer evaluates the data and issues instructions to respond to deviations from the required values. Another important factor for this application is the humidity resistance of all equipment used because it is too close to water.

·System architecture
In this application, the temperature of the water is measured with a thermocouple. The thermocouple is connected to an Advantech ADAM-4011 analog input/output module, which converts the thermocouple readings to digital ASCII signal outputs. These output signals are transmitted to the host computer through a multi-point RS-485 network. The computer compares the input temperature with a set of temperature limits pre-set using VisiDAQ 3.1 software. When the reading is outside the acceptable range (10°~35°), the computer sends an ASCII command to the Advantech Relay Output Module (ADAM-4060) to turn the heater on or off to return the water temperature to an acceptable value. The sensor reads the dissolved oxygen content and pH to produce the mV signal. These sensors are connected to Advantech ADAM-4011 and ADAM-4012 analog input modules. The ADAM module converts the values ​​received from these sensors into digital engineering unit signals and transmits them to the host through the RS-485 network. The computer compares the data readings with pre-defined pH and oxygen limits. If the input falls outside the acceptable range, the computer will inform the operator to change the water to return the oxygen content and pH to the appropriate level.

·in conclusion
The system uses ADAM modules to effectively control the water quality of fish and shrimp farms. The water quality history can also be generated by the VisiDAQ 3.1 software for analysis.