varioport is a very small and lightweight recorder system for all kind of physiological data. The recorder has sixteen analog inputs which are digitized by two AD-converters with a resolution of 16 bits. Additionally the recorder has a digital marker channel and allows to supervise and store its battery voltage. Together with the storage medium and the bat-teries the device is as small as a cigarette box.

　　The workflow of the recorder is controlled by a so called “definition file” which is generated on a PC with the VARIOGRAF software. This file defines which channels are recorded including sample rate and possible preprocessing (for example the calculation of the pulse frequence out of the raw ECG signal). The definition file also contains factors to convert the values of the AD converters into physical values (for example microvolts or degrees Celsius). For all recorder actions this definition is transferred from the PC to the recorder and is stored there in a RAM memory until the recorder is switched off. It is also possible to store a definition file in an EEPROM memory of the recorder. This file will be kept until it is overwritten by a new one. So it is possible to start the recorder also when no PC or Laptop is available.