Ophir Optronics Ltd QSR Manuel D’Utilisation

You can set the External Trigger to use one of four available input modes: Rising 
Edge, Falling Edge, High Level, or Low Level.  

Rising Edge 

•  The device is sensitive to a trigger on the RISING 

EDGE of the input. 

•  The trigger is valid for a pulse arriving during a 

window of time before or after the active (rising) edge 
(see Figure 7-2 ).  

•  The inactive (falling) edge of the signal is ignored. 
•  Missing Pulses are recorded when an External Trigger 

edge is received, but no pulse arrives within the 
Window Time before or after the active edge. 

•  Pulses are ignored if they arrive outside the Window 

Time, before or after the active edge. 

•  Multiple pulses within the Window Time are counted 

as one pulse. 

Falling Edge 

•  The device is sensitive to a trigger on the FALLING 

EDGE of the input. 

•  The trigger is valid for a pulse arriving during a 

window of time before or after the active (falling) edge 
(see Figure 7-2 ). 

•  The inactive (rising) edge of the signal is ignored. 
•  Missing Pulses are recorded when an External Trigger 

edge is received, but no pulse arrives within the 
Window Time before or after the active edge. 

•  Pulses are ignored if they arrive outside the Window 

Time, before or after the active edge. 

•  Multiple pulses within the Window Time are counted 

as one pulse. 

High Level 

•  Pulses are recorded only when the input signal is at a 

HIGH LEVEL. 

•  Any pulse arriving while the signal is high is counted. 

Any pulse arriving while the signal is low is ignored. 

•  No Missing Pulses are recorded in this mode. 

Low Level 

•  Pulses are recorded only when the input signal is at a 

LOW LEVEL. 

•  Any pulse arriving while the signal is low is counted. 

Any pulse arriving while the signal is high is ignored. 

•  No Missing Pulses are recorded in this mode. 

The following figure describes the External Trigger Window Time with the Rising 
Edge mode selected.