Fully programmable data logging unit with graphing capability for up to 8 inputs of 0 to 5 or 0 to 10 volts or 0 to 20 or 4 to 20mA d.c. Logging rate adjustable from 5 to 60 seconds or 1 to 60 minutes. The unit is connected to the users’ PC by USB serial connection and to the input device by a terminal trip. Supplied with operating software on a USB memory stick.