The Unit
Datalogger DL844 can read up to 8 analog voltages and 4 digital channels. 4 current sources are available for resistive sensor supply. A sigma-delta AD converter with integrated multiplexer is used to convert the analog signals. Data can be time-stamped with internal battery-backed clock and stored to an SD card. FAT formatted data enables simple data readout using a personal computer.
Real-time access to the data is possible over RS-485 bus, whereas USB interface is provided for direct access to the SD card when data logging is inactive. A microcontroller LPC2368 running operating system NTKernel is in charge for control of the unit. Various supply options are available including internal rechargeable battery.
The datalogger is due to its universality useful in many applications. In our laboratory it is also being used for monitoring of our dye sensitized solar cells.