Timer/Counter Mode: Uni
-
and Bi
-
directional Frequency/RPM Measurement
Used to measure any kind of frequency like engine RPM, or active sensors with proportional frequency output signal.
Signal
∆s ∆h
Direction
∆w
∆w
Figure A.131:
Uni
-
and Bi
-
directional count timing
Inputs
2 pins: signal, direction
Maximum input frequency
5 MHz
Minimum pulse width (Δw)
100 ns
Accuracy
0.1%, when using a gate measuring time of 40 μs or more.
With lower gate measuring times, the real
-
time calculators or Perception formula database
can be used to enlarge the measuring time and improve the accuracy more dynamically
e.g. based on measured cycles.
Gate measuring time
Sample period (1 / sample rate) to 50 s
Can be selected by user to control update rate independent of sample rate
Direction input
Level sensitivity
Only used when in bi
-
directional frequency/RPM mode
Low: Positive frequency/RPM, e.g. left rotations
High: Negative frequency/RPM, e.g. right rotations
Minimum setup time prior to signal edge (Δs)
100 ns
Minimum hold time after signal edge (Δh)
100 ns
GEN3i
538
I3763-3.1 en HBM: public
