I have created this pipeline:
def create_pipeline(SETTINGS):
    # Create pipeline
    pipeline = dai.Pipeline()
    # Define INPUT RGB camera
    camRgb = pipeline.create(dai.node.ColorCamera)
    # camRgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_1080_P)
    camRgb.setBoardSocket(dai.CameraBoardSocket.CAM_A)
    camRgb.setPreviewSize(300, 300)    # NN input
    camRgb.setInterleaved(False)
    camRgb.setPreviewKeepAspectRatio(False)
    camRgb.setFps(int(SETTINGS['NN']['fps']))
    # Define INPUT MONO-RIGHT camera
    monoRight = pipeline.create(dai.node.MonoCamera)
    monoRight.setCamera("right")
    monoRight.setFps(int(SETTINGS['NN']['fps']))
    # monoRight.setNumFramesPool(8)
    monoRight.setResolution(dai.MonoCameraProperties.SensorResolution.THE_400_P)
    # Define INPUT MONO-LEFT camera   
    monoLeft = pipeline.create(dai.node.MonoCamera)
    monoLeft.setCamera("left")
    monoLeft.setFps(int(SETTINGS['NN']['fps']))
    # monoLeft.setNumFramesPool(8)
    monoLeft.setResolution(dai.MonoCameraProperties.SensorResolution.THE_400_P)
    
    # Define OUTPUTS
    nnOut = pipeline.create(dai.node.XLinkOut)
    nnOut.setStreamName("nn")
    disparityOut = pipeline.create(dai.node.XLinkOut)
    disparityOut.setStreamName("disparity")
    xoutRight = pipeline.create(dai.node.XLinkOut)
    xoutRight.setStreamName("rectifiedRight")
    xout_color = pipeline.create(dai.node.XLinkOut)
    xout_color.setStreamName("video")
    # Define COMPUTE-NODES
    stereo = pipeline.create(dai.node.StereoDepth)
    manip = pipeline.create(dai.node.ImageManip)
    nn = pipeline.create(dai.node.MobileNetDetectionNetwork)
    
    stereo.setDefaultProfilePreset(dai.node.StereoDepth.PresetMode.DEFAULT)
    # stereo.setDefaultProfilePreset(dai.node.StereoDepth.PresetMode.HIGH_DENSITY)
    stereo.setRectifyEdgeFillColor(0) 
    
    manip.initialConfig.setResize(300, 300)
   
    manip.initialConfig.setFrameType(dai.ImgFrame.Type.BGR888p)
    nn.setConfidenceThreshold(float(SETTINGS['NN']['confidence']))
    nnPath = str((Path(__file__).parent / Path(str(SETTINGS['NN']['blob_path']))).resolve().absolute())
    nn.setBlobPath(nnPath)
    nn.setNumInferenceThreads(2)
    nn.input.setBlocking(False)
    # Linking
    camRgb.video.link(xout_color.input)
    monoRight.out.link(stereo.right)
    monoLeft.out.link(stereo.left)
    stereo.rectifiedRight.link(manip.inputImage)
    stereo.disparity.link(disparityOut.input)
    manip.out.link(nn.input)
    manip.out.link(xoutRight.input)
    nn.out.link(nnOut.input)
    return pipeline
and I'm using it in this way in order to process with NN the mono frame with IR enabled (for night-vision):
def Tracking(SETTINGS, selected_devices):
    DETECTED_OBJ=json.loads(SETTINGS['NN']['object'])
    pipeline = create_pipeline(SETTINGS)
    print("PIPELINE CREATED")
    devices = {}
    # Connect to device and start pipeline
    with contextlib.ExitStack() as stack:
        for device_info in selected_devices:
            openvino_version = dai.OpenVINO.Version.VERSION_2021_4
            usb2_mode = False
            device = stack.enter_context(dai.Device(openvino_version, device_info, usb2_mode))
            # Note: currently on POE, DeviceInfo.getMxId() and Device.getMxId() are different!
            print("\n==> Connected to " + device_info.getMxId())
            mxid = device.getMxId()
            device.startPipeline(pipeline)
            device.setIrLaserDotProjectorIntensity(0) # in %, from 0 to 1
            device.setIrFloodLightIntensity(0.9) # in %, from 0 to 1 
            devices[mxid] = {
                'nn': device.getOutputQueue("nn", maxSize=4, blocking=False),
                'mono': device.getOutputQueue("rectifiedRight", maxSize=4, blocking=False),
                'rgb':device.getOutputQueue("video", maxSize=4, blocking=False),
                'disparity':device.getOutputQueue("disparity", maxSize=4, blocking=False),
            }
...
I notice that the IR intensity is enabled only for the first frames.
Is it correct the pipeline and the IR intensity parameters?
Thank you