The MiniTest is a simple hand-held battery powered DMX512 tester with build in XLR plug. Even if the tester is powered by a 9V battery it has no on/off switch. The switching is done by sensing the plug: if a connector is plugged in, the tester switches automatically on, about one second after removing it switches off again.
The MiniTest does a complete protocol analysis: it checks the signals polarity, measures the break time with incredible 500ns resolution, reads the start-code, checks the two stop bits following the start-code, measures the number of slots/frame and measures the frame update rate with 0.1 frames/second resolution. The result is then evaluated by displaying it on a three digit ultra bright and battery saving 7-segment display. All interesting information is displayed for one second followed by the next. If the polarity is inverted the tester displays first "nEG", if the break time is below 88µs it will display "BrE", followed by the number of slots/frame and the frame update rate.