Estimate Pulse Detection Risk
This tool gives a practical estimate for whether a standard PLC input and cyclic logic scan are likely to catch an incoming pulse. It is intended for controls engineers, technicians, and automation designers doing first-pass troubleshooting or design review.
It is most useful when someone says, “the sensor definitely flashed, but the PLC never saw it,” or when you are trying to decide whether regular logic is enough or if you need a hardware latch, event task, or high-speed input.
Practical recommended pulse width = conservative minimum × safety margin
Need help applying this to a real machine?
Get connected with a qualified automation integrator if you are chasing missed counts, unreliable sensor pulses, reject confirmation problems, or fast event capture issues in production equipment.
Find an IntegratorThis is a practical engineering estimate, not a guaranteed hardware specification. Real capture behavior depends on PLC family, module type, firmware, task priority, debounce/filter settings, network delays, and whether the signal is local, remote, or latched in hardware.
What usually causes missed pulses
Most missed input events come from one of five things: the pulse is too short, the input filter is too long, the input is remote and updated too slowly, the logic task is too slow, or the application really needed a hardware latch or high-speed input from the beginning.
If the pulse width is anywhere near the PLC’s cyclic timing, assume risk. That is exactly when standard logic starts becoming unreliable for counting, edge capture, and fast sensor events.