customer recently needed to add local data logging and remote data transmission to a 50-year-old instrumentation panel.
This particular application required monitoring of an operator panel built before the days of data loggers. The engineers required measurements from the panel to be logged and to be able to monitor them remotely. The instrument panel was old and its scaling was not known, however, all display instruments were 4-20mA.
A Fluke 744 calibrator was used to check the scaling and a Datataker DT80M was employed to subsequently record, display and transmit values from the panel. Instrument scaling and their internal shunt resistors were determined using a Fluke 744 calibrator set to 4mA and 20mA.
The data logging solution was to be based on measuring the voltages developed across these existing shunt resistors to avoid breaking the loop or having additional resistors in the network. The shunts ranged from 100 to 2,500 ohms, which in the case of the 100 ohm resistor meant that the voltage range was quite low (0.04 to 0.2V).
The Datataker DT80M data logger was selected for having a differential input and an appropriate sampling rate capable of making accurate measurements in an industrial environment. Additionally, Datataker DT80M is readily configured to connect to the mobile phone network, while its automatic and alarm triggered data transmission capabilities enable data to be automatically emailed to multiple addresses or communicated via SMS messaging.
The Datataker DT80M's dEX logger software was configured to display the panel readings appropriately on the Datataker's password protected web interface. dEX datalogger software is an intuitive graphical interface that allows remote logger configuration, view of real-time data in mimics, trend charts or tables and retrieval of historical data for analysis.
The logger was also programmed to send summary data in a CSV file to the appropriate email addresses and a number of alarm conditions were also configured to send SMS messages when different criteria were met.
The Datataker's modem auto configured itself and connected to the mobile network, enabling engineers based at a different location to login and observe real time instrumentation panel measurements, and to receive the daily email reports.
TechRentals’ test and measurement equipment comprising of a Fluke 744 calibrator and a Datataker DT80M data logger enabled a 50-year-old industrial control panel to be monitored from anywhere simply using its IP address and appropriate passwords.