DI-2160 Event, State, and Count Data Logger
30
AC
vs
HS
Counter
Modes
The decision to apply the DI-2160’s HS (high-speed) or AC (alternating current) counter mode depends
upon what information is desired from the measurement. The high-speed counter mode is used when you
need to total each pulse that occurs within a sample interval. A flow sensor with a pulsed output is a good
example, where each pulse represents an incremental flow value and therefore carries information. But
what if you’re interested only in the number of times a 120V/60Hz fan by was activated within a six-hour
sample interval?
Use of the HS counter mode in this situation yields the number of 60 Hz pulses that
occurred during that time – not exactly what you want. The AC counter mode is optimized to ignore 50/60
Hz power line transitions and to change state only when power is removed or applied. Applying the AC
Counter mode to the fan application provides exactly the information you need – the number of times the fan
activated within successive six-hour periods.
