Versatile All-in-One Data Logger for Monitoring and Control Applications
A CAS Data Loggers customer who had recently purchased a dataTaker DT80 intelligent data logger called in looking for advice on how to set it up to not only control a hydraulic valve used in materials testing, but also to only log data when the hydraulic valve was active. This would enable the user to save memory on the dataTaker and streamline data organization. Our Applications Specialists have put together this quick tutorial showing how it was done in dEX, the built-in interface included on all dataTaker dataloggers.
The control measurement for the valve is a simple linear transducer, and the customer wants the valve and logger to run only when this transducer is under a certain voltage value. The valve is wired directly to the 12-volt DC output from the DT80, so all that needs to be done to run the valve is to turn on the power to that output using a simple command in dEX.
The program is a 2-schedule program that uses a non-logging schedule to check the transducer measurements to see if the value is such that the valve should be opened, and the logger should begin logging. When the correct conditions are met, this schedule then sets a channel variable equal to 1, and turns on the correct power supplies.
The second schedule is setup to run when the CV that is changed in Schedule A is a non-Zero value.
Schedule B records the transducer output and performs a scaling calculation. It then watches the transducer to see if it drops below the desired value to open the valve. When it drops below this value, an alarm sets the CV back to 0 and turns off the power supplies.
Before installation, the user had to closely watch the entire process to manually turn off the power, so the DT80’s control functionality saves him significant time. Additionally, all the data retrieved from the logger is relevant since it has all been logged during the valve’s operation. This saves the user all the hassle otherwise spent looking over the entire data for the significant parts.
dataTaker data loggers feature universal input channels for use with a wide range of input signal types and can record: Temperature, Voltage, Current, 4-20mA Loops, Resistance, Bridges, Strain Gauges, Frequency, Digital, Serial and Calculated Measurements. They also offer powerful alarm and programming capabilities to allow the loggers to process measurements and initiate actions on their own.