User`s manual

PC2-CamLink User's Manual Part I: PC2-CamLink Board • 29
Let:
t(et) = time of external trigger in μs
t(vt) = time of validated trigger in μs
t(d) = debounce circuit duration from 0 to 255μs
We therefore get:
t(vt) = t(et) – t(d)
If:
t(vt)> 0, then a valid trigger is detected and acquisition is fired
Opto
Formed by a LED emitter combined with a photo detector in close proximity, an opto-coupler (or
opto-isolator) allows for the connection between the PC2-CamLink external trigger and the user
circuitry using separate grounds. This ‘galvanic isolation’ prevents ground loops and protects both
circuits. A jumper-selectable resistor is connected in serial fashion to the opto-coupler to limit the
current.
Both opto-coupled triggers allow serial resistor selection that is used to limit the current flowing
through the diode. This is seen in the following tables.
OPTO1:
Jumper Voltage Selection Serial Resistor
J5 12V 1.33 KΩ
J6 5V 221Ω
Note: Only select jumper J5 or J6, not both simultaneously.
OPTO2:
Jumper Voltage Selection Serial Resistor
J3 12V 1.33 KΩ
J4 5V 221Ω
Note: Only select jumper J3 or J4, not both simultaneously.