GPIO problem sending TTL

Answered

Max L

• September 14, 2023 19:53

Hello,

I am trying to synchronize video from my Blackfly S USB3 camera with another data stream using a National Instruments DAQ by sending a TTL pulse on each frame capture. I have the white wire (opto-isolated output) from the 6-pin GPIO cable connected to a digital I/O terminal block on my DAQ but I'm not seeing any signal going through. Below are the settings I have on the software, but I'm not sure if it's correct. Any help would be appreciated

 

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• Official comment

  

  TDY_Markus

  Community team

  • September 15, 2023 12:10

  

  

  Hi Max,

  Your settings look correct for configuring output at Line1 (white). 

  Did you connect Opto GND (blue) to the Ground of your NI DAQ?
  Also, opto-isolated outputs require a pull-up resistor which is connected to a voltage (E.g. Pin 3, Camera Power Output). Then you also need to connect the Ground of this voltage (E.g. Pin 6, GND) to the Ground of your NI DAQ.

  Another possibility would be to use a non-isolated output pin like Line 2. Then you just need to connect Line 2 (red) and GND (brown) to your NI DAQ.

  Please let me know if this helps to solve the issue.

  Thanks,
  Markus
• 

  TDY_Ifeanyi

  Community team

  • September 15, 2023 11:23

  

  

  Hello Max,

  Opto-isolated GPIO output line require pull-up voltage to strengthen the signal. Following similar configuration as we describe in this article https://www.flir.com/support-center/iis/machine-vision/application-note/configuring-synchronized-capture-with-multiple-cameras/ for synchronizing BFS cameras, I would enable 3.3V in Line2 with 10 KOhms resistor to boost signal strength. 

  Thanks,

  Ifeanyi

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• 

  TDY_Markus

  Community team

  • September 21, 2023 12:51

  

  

  Hi Max,

  I just wanted to check-in on this.
  Did it work for you?

  Thanks,
  Markus

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• 

  Max L

  • November 16, 2023 22:06

  Hi, unfortunately the suggestions did not seem to fix our issue. Is there anything else to help troubleshoot our problem? 

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• 

  TDY_Ifeanyi

  Community team

  • November 20, 2023 15:01

  

  

  Hello Max,

  Have you tried measuring TTL signal from opto-isolated output wire (white colour) using oscilloscope? Is there any specific reason for using opto-isolated pin? Otherwise, I will recommend using non-opto Line2/Line3 with line mode configured as output. 
  
  Please let us know if any of the provided information help to resolve this.

  Thanks,

  Ifeanyi

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• 

  TDY_Ifeanyi

  Community team

  • December 13, 2023 14:56

  

  

  Hi Max,

  I just wanted to make sure you saw my last email.

  Please let us know if you have any questions about it.

  Best Regards,

  Ifeanyi

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