john-judge
commented
3 years ago From Meyer:
" In addition to acquiring images the program performs a concurrent read of auxiliary data lines. Those reads must be initiated simultaneously with the camera’s reading of images and the timing must be maintained so that we know which analog data point corresponds to which image. Photoz reads 8 inputs but we only use 2 or 3. I think Chun’s program reads in 4 analog lines. The camera came with 4.
In photoz the analog input data becomes fp_data and fp_data. The fp stands for ‘field potential’, which is what some of the analog data is.* A field potential is recorded by an electrode positioned in the brain slice, amplified by an amplifier, and digitized by the interface. However, we mostly use these analog signals for other purposes.
The NI-USB supplies digital outputs for the following purposes
- Trigger the camera to start reading images
- Control the LED (it used to be opening and closing a shutter – same idea)
- Supplying digital pules to a stimulator that when triggered produces an analog pulse. We need two of these. "
*In the 2006 hVOS paper, Meyer/Payne used the analog input for patch clamp electrodes, in which case it really was local field potential (LFP)
What's the purpose of line 189 of DapController.cpp, in DapController::acqui? My thought is that maybe DAQmxReadBinaryI16 is blocking and used for stimulus/camera synchronization. We call DAQmxReadBinaryI16 but never end up using or freeing the samples array in "buf" nor the number of input samples. It seems that similarly in SM_take_tb-Chun.cpp that Chun's examples used DAQmxReadAnalogF64 for the sections for NI Acquisition to read in AI channels, but I don't seem to see where the analog input data gets used.
We seem to read in image data from Camera -> DataArray (managed in driver MainController -> DapController). So is it accurate to say that PDV does all the image data acquisition (frame grabbing)?
What data if any do we need to read into PhotoZ through NI-DAQmx? Is it accurate to say that NI-USB is solely for administering/timing stimuli (as digital output)?