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Community Manager

RuntimeError: Failed to queue inference: NC_ERROR - after 100 Frames // NCS2 Raspberry pi

Hi there,


I tried to change the classification sample, to work with my video and own model, and it runs on my i with 2 NCS2, but after approximtely 100 frames it starts to freeze and then gives me the following error msg:


Traceback (most recent call last):


File "/home/pi/NCS_OpenVino/", line 131, in


res = exec_net.infer(inputs={input_blob: images})


File "ie_api.pyx", line 146, in openvino.inference_engine.ie_api.ExecutableNetwork.infer


E: [watchdog] [ 990982] sendPingMessage:164 Failed send ping message: X_LINK_ERROR


File "ie_api.pyx", line 179, in openvino.inference_engine.ie_api.InferRequest.infer


File "ie_api.pyx", line 183, in openvino.inference_engine.ie_api.InferRequest.infer


RuntimeError: Failed to queue inference: NC_ERROR


E: [ncAPI] [ 991550] ncFifoDestroy:2888 Failed to write to fifo before deleting it!


i tried to delete my variables and load the model again every 40 frames, cause I thought it might be a allocation error, but didn't change a thing.


any clues??




from future import print_function


import imutils


import sys


import os


from argparse import ArgumentParser


import cv2


import numpy as np


import logging as log


from time import time


from openvino.inference_engine import IENetwork, IEPlugin


from import FileVideoStream


from import FPS


from import VideoStream


from import FPS


import argparse


import imutils


import cv2 as cv


import numpy as np


from import FileVideoStream


import os


import matplotlib.pyplot as plt


def build_argparser():


parser = ArgumentParser()


parser.add_argument("-m", "--model", help="Path to an .xml file with a trained model.", required=True, type=str)


# parser.add_argument("-i", "--input", help="Path to a folder with images or path to an image files", required=True,


# type=str, nargs="+")


parser.add_argument("-l", "--cpu_extension",


help="MKLDNN (CPU)-targeted custom layers.Absolute path to a shared library with the kernels "


"impl.", type=str, default=None)


parser.add_argument("-pp", "--plugin_dir", help="Path to a plugin folder", type=str, default=None)


parser.add_argument("-d", "--device",


help="Specify the target device to infer on; CPU, GPU, FPGA or MYRIAD is acceptable. Sample "


"will look for a suitable plugin for device specified (CPU by default)", default="CPU",




parser.add_argument("--labels", help="Labels mapping file", default=None, type=str)


parser.add_argument("-nt", "--number_top", help="Number of top results", default=10, type=int)


parser.add_argument("-ni", "--number_iter", help="Number of inference iterations", default=1, type=int)


parser.add_argument("-pc", "--perf_counts", help="Report performance counters", default=False, action="store_true")


return parser


if 1 == True:


#cap = VideoStream(usePiCamera=True).start() #time.sleep(2.0) cap = FileVideoStream('/media/videopath.mp4').start() log.basicConfig(format="[ %(levelname)s ] %(message)s", level=log.INFO, stream=sys.stdout) args = build_argparser().parse_args() model_xml = args.model model_bin = os.path.splitext(model_xml)[0] + ".bin" # Plugin initialization for specified device and load extensions library if specified plugin = IEPlugin(device=args.device, plugin_dirs=args.plugin_dir) if args.cpu_extension and 'CPU' in args.device: plugin.add_cpu_extension(args.cpu_extension) # Read IR"Loading network files:\n\t{}\n\t{}".format(model_xml, model_bin)) net = IENetwork(model=model_xml, weights=model_bin) if plugin.device == "CPU": supported_layers = plugin.get_supported_layers(net) not_supported_layers = [l for l in net.layers.keys() if l not in supported_layers] if len(not_supported_layers) != 0: log.error("Following layers are not supported by the plugin for specified device {}:\n {}". format(plugin.device, ', '.join(not_supported_layers))) log.error("Please try to specify cpu extensions library path in sample's command line parameters using -l " "or --cpu_extension command line argument") sys.exit(1) assert len(net.inputs.keys()) == 1, "Sample supports only single input topologies" assert len(net.outputs) == 1, "Sample supports only single output topologies""Loading model to the plugin") exec_net = plugin.load(network=net) framenr = 0 net.batch_size = 1 width1 = 1080 pxli = round(width1 / 2 - width1 * 0.022) pxre = round(width1 / 2 + width1 * 0.022) while(1): spf = time() frame1 = frame2 = imutils.resize(frame1, width=width1) frame1 = frame2[350:398, pxli:pxre] frame1 = cv2.resize(frame1, (224, 224)) args.input = frame1"Preparing input blobs") input_blob = next(iter(net.inputs)) out_blob = next(iter(net.outputs)) images = frame1 images = images.transpose((2, 0, 1)) # Change data layout from HWC to CHW #images[i] = image"Batch size is {}".format(1)) t1 = time() res = exec_net.infer(inputs={input_blob: images}) cv2.imshow("Frame", frame1)"Average running time of one iteration: {} ms".format((time()-t1)*1000)) # Processing output blob"Processing output blob") res = res[out_blob]"Top {} results: ".format(args.number_top)) if args.labels: with open(args.labels, 'r') as f: labels_map = [x.split(sep=' ', maxsplit=1)[-1].strip() for x in f] else: labels_map = None for i, probs in enumerate(res): probs = np.squeeze(probs) top_ind = np.argsort(probs)[-args.number_top:][::-1] #print("Image {}\n".format(args.input)) for id in top_ind: det_label = labels_map[id] if labels_map else "#{}".format(id) print("{:.7f} label {}".format(probs[id], det_label)) print("\n") key = cv.waitKey(1) if key == ord("q"): break print("FPS {} ".format(1/(time()-spf))) framenr +=1 print("#FRAME {}".format(framenr)) del images del input_blob del out_blob del res del frame1 del probs del frame2 if framenr > 40: del exec_net exec_net = plugin.load(network=net) framenr = 0



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2 Replies
Community Manager

Hi @Tonto5000


The Failed send ping message: X_LINK_ERROR message is probably due to a connection issue between the NCS2 and the system. Since you're using a Raspberry Pi, are you plugging the NCS2 straight in to the Pi, or are you using a powered USB hub?


Best Regards,





Is this issue resolved? I am experiencing a very similar problem and I am wondering if you can help me with that.


I am using NCS2 and OpenVINO on Raspberry Pi 3 and I am trying to run a very simple inference from a costume Pytorch model (single layer Conv1d). I used OpenVINO on Mac for generating the model and converted it using the deployment_tools:


python3 /opt/intel/openvino_2019.2.242/deployment_tools/model_optimizer/ --input_model test.onnx --data_type FP16


While I can simple perform the inference on Mac, I get the following error about failing to queue inference. Can you help with this? (please find the logs leading to error at the end of the message.)


Thanks for you support!






[ INFO ] Creating Inference Engine

[ INFO ] Loading network files:



[ INFO ] Preparing input blobs

[ INFO ] Loading model to the plugin

[ INFO ] {'x': <openvino.inference_engine.ie_api.InputInfo object at 0x60729290>}

[ INFO ] {'3/reshape_back': <openvino.inference_engine.ie_api.OutputInfo object at 0x60721d40>}

[ INFO ] Starting inference in synchronous mode



RuntimeError               Traceback (most recent call last)

<ipython-input-10-5bfc300eb881> in <module>()

   73 print (inp.shape)


---> 75 ema_openvino = main(inp)


<ipython-input-10-5bfc300eb881> in main(x)


   60"Starting inference in synchronous mode")

---> 61   res = exec_net.infer(inputs={'x': signal_input})


   63   output = res['3/reshape_back']


ie_api.pyx in openvino.inference_engine.ie_api.ExecutableNetwork.infer()


ie_api.pyx in openvino.inference_engine.ie_api.InferRequest.infer()


ie_api.pyx in openvino.inference_engine.ie_api.InferRequest.infer()


RuntimeError: Failed to queue inference: NC_ERROR