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Advanced Pulse Counter: Difference between revisions

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Advanced Pulse counter functionality has limitations when pulse is at different duty cycle and signal voltage at 2kHz frequency. Exceeding limitations might lead to unexpected pulse count or even stop functionality from working. Tables below shows those limitations for specific DIN.
Advanced Pulse counter functionality has limitations when pulse is at different duty cycle and signal voltage at 2kHz frequency. Exceeding limitations might lead to unexpected pulse count or even stop functionality from working. Tables below shows those limitations for specific DIN.


Devices on DIN2 support up to 2kHz pulse frequency. Pulses can be with different duty cycles, but only pulses that are greater than 120us period is counted, otherwise they are filtered as signal noise. In other words, pulse change between low and high state should not take longer than 120us. Also, there is a pulse rise time that affects time when voltage threshold is reached. So, for 2kHz there is limitations for available duty cycle.
Devices on DIN2 support up to 2kHz pulse frequency. Pulses can be with different duty cycles, but only pulses that are greater than 120μ period is counted, otherwise they are filtered as signal noise. In other words, pulse change between low and high state should not take longer than 120μ. Also, there is a pulse rise time that affects time when voltage threshold is reached. So, for 2kHz there is limitations for available duty cycle.


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For lower than 2kHz frequencies smaller or bigger duty cycle might be available, considering previously mention conditions.
For lower than 2kHz frequencies smaller or bigger duty cycle might be available, considering previously mention conditions.


Also, devices that’s support 2kHz on DIN1 (see Table 1) have same limitations as DIN2, but also minimum voltage provided to DIN1 by pulse should be 7.5V or grater. Lower than 7.5V pulses add pulse rise time. For example, at 3.6V pulse rise time is ~500us comparing to 7.5V at 60us (FMB920). Pulse counting might work at these low voltages with low frequency but it is not reliable.
Also, devices that’s support 2kHz on DIN1 (see Table 1) have same limitations as DIN2, but also minimum voltage provided to DIN1 by pulse should be 7.5V or grater. Lower than 7.5V pulses add pulse rise time. For example, at 3.6V pulse rise time is ~500μ comparing to 7.5V at 60μ (FMB920). Pulse counting might work at these low voltages with low frequency but it is not reliable.


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