| Functionality |
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Troubleshooting using the LFSR
To control the quality of your complete imaging system enable the LFSR mode, set the camera window to 1024 x
1024 pixels (x=0 and y=0) and check the histogram. If your frame grabber application does not provide a real-time
histogram, store the image and use a graphic software tool to display the histogram.
In the LFSR (linear feedback shift register) mode the camera generates a constant pseudo-random test pattern
containing all grey levels. If the data transmission is error free, the histogram of the received LFSR test pattern will
be flat. On the other hand, a non-flat histogram indicates problems, that may be caused either by the cable, by the
connectors or by the frame grabber.
Figure 30: LFSR test pattern received at the frame grabber and typical histogram for error-free data
transmission
Figure 31: LFSR test pattern received at the frame grabber and histogram containing transmission
errors
Note:
A possible origin of failure message can be caused by the Camera Link cable which exceeds the
maximum length. Also, Camera Link cables may suffer either from stress due to wrong installation or from
severe electromagnetic interference.
Note:
Some thinner Camera Link cables have a predefined direction. In these cables not all twisted pairs are
separately shielded to meet the RS644 standard. These pairs are used for the transmission of the RX/TX and
for the CC1 to CC4 low frequency control signals
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