National Instruments NI 17xx Manual De Usuario

© National Instruments Corporation

The smart camera automatically synchronizes the lighting strobe with the 
image sensor exposure. The smart camera always turns the light on before 
an exposure starts and turns the light off once the exposure completes. 
The duration of the light strobe is dictated by the exposure time. Refer to 
Chapter 5, 

, for more information.

When operating in strobed mode, it is important that the strobe duty cycle 
and strobe duration are within the specified limits of both the light and the 
Direct Drive lighting controller. The strobe duration is the amount of time 
that the light remains on. The strobe duration limit is the maximum amount 
of time that the light can remain on when being driven at the maximum 
current. The duty cycle is the ratio of the strobe duration to the frame 
period, expressed as a percentage. Refer to the 

 

section of Chapter 5, 

, for more information about the 

frame period.

By default, you can set the exposure time to any setting within the range 
supported by your smart camera. However, if the smart camera is 
configured to use the Direct Drive lighting controller in strobed mode, care 
must be taken to ensure that the resulting strobe duty cycle and strobe 
duration do not violate the limits of the Direct Drive lighting controller or 
the limits of the light. For your convenience, the software calculates the 
resulting strobe duration and duty cycle for your configured frame rate and 
exposure time. It then compares them to the limits of the Direct Drive 
lighting controller and the limits specified in the associated lighting file. 
Refer to the 

 section of this chapter or the 

 section of Chapter 5, 

, for more information.

If the requested exposure time violates the limits of the Direct Drive 
lighting controller or the limits for your light as specified in the associated 
lighting file, the smart camera can use the requested exposure time, but 
requires the configured current to be at or below the maximum continuous 
current.

If you are using the 5 V strobe output or the 24 V strobe output, the software does 

not impose any limits on the duration or the duty cycle of the strobe output. You must 
ensure that your requested exposure time and the frame rate result in duration and duty 
cycle that do not violate the limits of the external controller and/or light(s). Refer to the 

 section of Chapter 5, 

, for more information.