Acquisition of frames lags before reaching the desired number of frames

Description I am facing the following issue. I am using Harvesters to acquire photos from two usb 3 cameras (GO-5000M-USB). In my application the two cameras should start at the same time (there is a small delay between the two cameras as I am not using a hardware trigger but It is acceptable) then acquire a certain number of frames with a pre defined frame rate (1 fps). I wrote a simple python script that performs this procedure. Sometimes the script just lags before reaching the desired number of frames (for example I want to acquire 500 frames but it just stops at 43 frames). When this happens I can only exit the terminal and run the script again. The main issue is I don't have the required number of frames per run. I am doing material testing so when I run the script I also run some mechanical testing machine. When the script stops in the middle of an experiment I lose information due to not recording all the frames.

To Reproduce Steps to reproduce the behavior:

Run python file in terminal

The script

from harvesters.core import Harvester
import cv2
import os
import sys
import numpy as np

width = 2560
height = 2048
sdk_cti_path = r'C:\Program Files\JAI\SDK\bin\JaiUSB3vTL.cti'
cam1 = {'serial_number': 'U502186'}
cam2 = {'serial_number': 'U502937'}

#---------------------------------------------------------------------------------------
# Functions
#---------------------------------------------------------------------------------------

def init_two_cameras(cam1, cam2, sdk_cti_path, fps):
    """Function to initiate a computer vision camera"""

    # Create harvester object 
    h = Harvester()
    h.add_file(sdk_cti_path)
    h.update()

    # Create image acquirer
    ia1 = h.create(cam1)
    ia2 = h.create(cam2)

    # Control fps
    ia1.remote_device.node_map.AcquisitionFrameRate.value = fps
    ia2.remote_device.node_map.AcquisitionFrameRate.value = fps

    # Start aquisition
    ia1.start()
    ia2.start()

    return h, ia1, ia2 

def shut_camera(image_acquirer, harvester):
    """function to shut down the camera"""
    image_acquirer.stop()
    image_acquirer.destroy()
    harvester.reset()

#-----------------------------------------------------------------------------------------------------------------
# Main 
n_frames_cam1 = 500 # Number of frames required for camera 1
n_frames_cam2 = 500 # Number of frames required for camera 2
fps = 1 # Number of frames per second 

#------------------------------------------------------------------------------------------------------------

h, ia1, ia2 = init_two_cameras(cam1, cam2, sdk_cti_path, 1)

# Acquire frames and write to disk
counter = 0
for i in range(n_frames_cam1):
    with ia1.fetch() as buffer:  
        #create an alias of the 2D image component:
        component = buffer.payload.components[0]

        #Reshape the NumPy array into a 2D array:
        frame = component.data.reshape(component.height, component.width)

        # convert to bgr
        frame = cv2.cvtColor(frame, cv2.COLOR_GRAY2BGR) 

        # save a snapshots
        cv2.imwrite('cam1_' + str(i) + '.jpg', frame)

    with ia2.fetch() as buffer:
        #create an alias of the 2D image component:
        component2 = buffer.payload.components[0]

        #Reshape the NumPy array into a 2D array:
        frame2 = component2.data.reshape(component2.height, component2.width)

        # convert to bgr
        frame2 = cv2.cvtColor(frame2, cv2.COLOR_GRAY2BGR) 

        # save a snapshots
        cv2.imwrite('cam2_' + str(i) + '.jpg', frame2)

    counter = counter +1
    print(counter)

shut_camera(ia1, h) 
shut_camera(ia2, h)

Expected Behavior I expect all the frames from both cameras to be acquired and saved safely.

Configuration

OS: [Windows 11, 64 bit]
Python: [3.7.6]
Harvester: [1.4.0]
GenTL Producer: [JAI SDK version 3.0.7]
Camera: [GO-5000M-USB]

Reproducibility

This phenomenon can be stably reproduced:

[ ] Yes
[X] No. Sometimes the script works normally when I shut down and start the machine (records the desired number of frames). However most of the times It just stops before reaching the required number of needed frame (eg. at frame 25)

Actions You Have Taken

[x] I've read the Harvester FAQ page.

genicam / harvesters

Acquisition of frames lags before reaching the desired number of frames #400