Pulse repetition
Pulse repetition is calculated as follows:
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Note
Pulse width must be selected with the view that remaining time is always greater than pulse
width at the highest measured flow.
Example
● Pulse output configuration (channels 2 to 4)
– Operation mode = Pulse output
– Process value = Mass flow
– Amount = 1 kg
– Pulse width = 1 ms
● Measured mass flow value = 10 kg/s (constant)
Result:
● Pulse repetition = 100 ms
● Output frequency = 10 pulses per second with a pulse width of 1 ms
● Remaining time between pulses is 99 ms
8.2.6.3
Frequency output
The frequency output function supplies a frequency (50% duty cycle) proportional to the
selected process value.
Frequency is calculated as follows:
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Example
This example shows how to calculate the output frequency for any measured flowrate:
Frequency output configuration:
● Operation Mode = Frequency Output (Channel 2 to 4)
● Process value = Mass flow
● Direction = Positive
Parameter assignment
8.2 Functions
SITRANS FC330
Operating Instructions, 01/2019, A5E44030648-AB
141