Externally-triggered exposure

Discussion in 'Aluma CCD Series' started by William Deich, Apr 5, 2022.

  1. William Deich

    William Deich Standard User

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    I am trying to do externally-triggered exposures, without success.

    I'm using dlapi v1.4 on CentOS 8.5.

    I made trivial modifications to the sample program (that comes with dlapi v1.4), so as to set the useExtTrigger flag. But this seems to have no effect: the exposure proceeds immediately, just as if I had not set the option. I have verified that my trigger source is normally low; and I also disconnected the trigger input entirely, with the same result.

    Does anyone have troubleshooting recommendations?

    thanks,
    -will
     
  2. Doug

    Doug Staff Member

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    Can you try it from MaxIm LT (or MaxIm DL Pro) on Windows? That should eliminate any potential hardware issue.
     
  3. Colin Haig

    Colin Haig Staff Member

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    Will, can you confirm is which camera model (e.g. Aluma CCD 47-10)? Do you know which FPGA firmware is in the camera?
    I've asked a colleague to get in touch as soon as we have that info.
     
  4. William Deich

    William Deich Standard User

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    Doug, running the Maxim software on Windows is surprisingly inconvenient for us -- I only have Linux and Mac OS choices where I am now -- but can do so if need be.

    Colin, correct, it's an Aluma CCD 47-10.
    Serial: AL4710M-21122001
    Firmware: 23
     
  5. William Deich

    William Deich Standard User

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    Doug, we'll install Maxim LT and connect the camera to a Windows host tomorrow. Are there any tests you recommend besides the basic check of "does the external trigger work under Maxim LT?"

    thanks,
    -will
     
  6. Doug

    Doug Staff Member

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    "Does the external trigger work under Maxim LT?" is exactly what we want.

    If it doesn't work, then it's probably a hardware issue.

    If it does work, it means the camera is fine and there's something on the software side. The Linux and Windows drivers share source code, so it is probably unlikely that the driver is to blame, but it's best to start eliminating things.

    Question: Do you have something connected to the trigger input? If so then what?
     
  7. William Deich

    William Deich Standard User

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    I tested two ways -- (1) with a simple pushbutton-activated 5V signal connected; and (2) with nothing connected at all.
    In the second case, I was expecting no exposure to be initiated at all.
     
  8. Doug

    Doug Staff Member

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    Right, so either it wasn't actually in trigger mode, or the input circuit is shorted out somehow.

    Our production test software is actually an add-on for MaxIm DL, which actually does all the talking to the camera. And that's how we test the trigger functions. So we know that software works for sure!
     
  9. William Deich

    William Deich Standard User

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    We have now had successful TriggerIn exposures using MaxIm LT.

    By comparison, in the unsuccessful test from Linux, I used the sample program in
    dlapi.sdk.linux_1.4.0-0_amd64/sample/main.cpp
    and did:
    1) Verified that it took ordinary timed exposures successfully;

    2) Changed one line from
    options.useExtTrigger = false;
    to
    options.useExtTrigger = true;

    but it exposed immediately on invoking pSensor->startExposure();
     
  10. Doug

    Doug Staff Member

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    Okay perfect - nothing wrong with the hardware.

    The code is shared for Windows and Linux, so it's a bit surprising that it would behave differently.

    I will have to refer this to @Adam Robichaud for driver support.
     
  11. Adam Robichaud

    Adam Robichaud Lead Developer Staff Member

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    The Linux 1.4 driver is admittedly a way older build than the one in MaxIm LT, so my money would be on there was a bug we fixed in a subsequent release.
    Will, I'm about to send you a private message involving a beta version of DLAPI. 2.1 on Linux.
     
  12. William Deich

    William Deich Standard User

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    Thanks, Adam, looking forward to it!
     

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