Pulse Output - GF PF220 V2 Betriebsanleitung

Operating Instructions
9.2.1

Pulse output

Select Pulse Output to measure Volume or Energy and then press Continue. Any other selection of Measurement Source will result
in an error.
The default pulse width is set to 50ms which represents half of a one pulse cycle. A 50ms pulse width is required for most
mechanical counters, but the width can be set as low as 10ms.
Volumetric Pulse
The quantity per pulse is usually set to a value that makes it easy to read an external pulse counter. For example, the value could
be 10 litres per pulse, which means that for every 10 litres of fluid measured by the meter, a pulse is generated. If the total rises
by 25 litres in a second, two pulses will be generated and the remainder of 5 litres will be held over. If, in the next second, another
25 litres are measured, this will be added to the remainder making a total of 30 litres. This will result in the meter generating 3
pulses.
A minimum idle time equal to the pulse-width, follows the pulse. There is a maximum pulse rate and hence maximum volumetric
flow that the pulse output can represent.
For the scenario mentioned above, if the volume per pulse is ϑ and the pulse width is ρ (ms), then the maximum flow rate is 500 ϑ/
ρ. In the example above, ϑ is 10 l/pulse and ρ is 50 ms, the maximum average flow rate is 500 * 10 / 50 = 100 l/s. This limit comes
from the inability to generate more than 10 pulses per second due to the 50ms pulse width and minimum 50ms idle time. Because
each pulse represents 10 litres, the output can only represent 100 l/s.
While this is the maximum average flow, it does not mean that transient flows of greater than this amount cannot be handled. The
flow meter can accommodate up to 1000 outstanding pulses. If this amount is exceeded, then an error will be generated. If the flow
rate is below the average, the pulse tally can be made up by a burst of pulses.
Pulse output
switch open
Pulse output
switch closed
0
Pulse Width
50 milliseconds
50 100 150 200
Time (milliseconds)
Default Pulse Width
250 300 350
Outputs
45