Key Digital ES381 manual Green means the reading is done

Green means the reading is done.

Red means the reading over-flowed i.e. external period too long or external frequency too high. Try a shorter internal period or lower internal frequency.

If the counter waits for more than 2 seconds whilst in Period mode and no external signal has been detected, the indicator will blink rapidly white-grey-white-grey etc.

Elan Digital Systems Ltd. 18 USBcount50 USER’S GUIDE Iss1