Hitachi SJ7002 Series Instruction Manual page 204

4–42
Using Intelligent Input Terminals
Pulse Counter
Signals
74=[PCNT]
Opt. Code
and
75=[PCC]
Symbol
Valid for
[1] to [8]
Inputs
Monitor
D028
Settings
Default
Requires
config.
terminal
The intelligent pulse counter input [PCNT] allows you to input a pulse train up to 100 Hz via an
intelligent input terminal. (For high-speed applications, use the encoder input expansion card
instead.) Monitor the cumulative count with D028, pulse counter function. The value of the
cumulative count cannot be stored in a separate register or parameter. The counter value is
cleared to zero when inverter power is turn ON or the inverter is reset. You may also use the
[PCC] Pulse Counter Clear input to clear the cumulative count.
The frequency resolution of the input pulse can be calculated by the formula shown below
(assuming a pulse signal input with 50% duty cycle). Do not input higher frequencies than the
calculated value.
Frequency resolution (Hz) = 250 / input terminal response setting (C160 to C168) + 1)
Example: When the input terminal response time = 1, the frequency resolution = 125 Hz
Pulse counter
input [PCNT]
Filtered
pulse train
Counter value 1 2
t
t
3 4