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Technical specifications
Z-Trak2 3D Profiler Sensors
External trigger usage
Input signal is debounced to ensure that no voltage glitch is detected as a valid transition. This
debounce circuit time constant can be programmed from 1
s to 255 µs. Any pulse smaller than
the programmed value is blocked and therefore not seen by the board. If no debounce value is
specified (value of 0 µs), the minimum value of 1 µs will be used.
Trigger signal total delay
Opto-Coupler
t(oc)
Debouncer
t(d)
External Trigger
t(et)
Validated Trigger
t(vt) = t(et) + t(oc) + t(d)
Figure 30: External trigger input validation and delay
where
t(et) = time of external trigger in µs
t(oc) = time opto-coupler takes to change state (also called propagation delay) (note: time varies
with input voltage)
t(d) = user set debounce duration from 1 to 255 µs
t(vt) = time of validated trigger in µs
If t(et) > t(oc) + t(d), then a valid acquisition trigger is detected.