Troubleshooting

If the Holoscan visualizer is not able to access the host display, the program will usually crash with a segmentation fault. Make sure that xhost +local:docker is executed on the host system before running the Holoscan application and make sure the DISPLAY environment variable is set properly in the container where the application is run.

The hololink enumerate command, in the demo container, can be used to monitor enumeration messages sent by the sensor bridge device. If no messages appear, then check for power to the sensor bridge device, physical connections to the device, and appropriate network configurations as listed above. ping 192.168.0.2 and ping 192.168.0.3 can also be used to check for connectivity.

If there are no error messages on the application console, then it indicates that the control plane is able to connect but there is no data being received on the data plane. For unaccelerated network connections, tcpdump can be used to determine if traffic is being sent from the sensor bridge device. In accelerated network configurations, the ConnectX NIC hides the data plane traffic from the CPU, so tcpdump will not report it. Instead, you can check the packet receiver counter this way:

            

            
cat /sys/class/infiniband/roceP5p3s0f0/ports/1/hw_counters/rx_write_requests
        

or, to see all counters published by the ConnectX driver,

            

            
for i in /sys/class/infiniband/roceP5p3s0f0/ports/1/counters/*; do
echo -n $i
echo -n ": "
cat $i
done
        

Use the appropriate value where roceP5p3s0f0 is shown here. When no data plane requests are received, be sure and check that the sensor is properly connected to the sensor bridge board.

The Holsocan Sensor Bridge board has two leds that depending on their state have the following indications:

1. Both leds are off - The Holoscan Sensor Bridge Board is not powered.

2. Both leds are on with green color - The Holoscan Sensor Bridge Board is powered and ready.

3. One green led or green led blinking - The Holoscan Sensor Bridge Board is powered with incorrect power supply that does not meet the minimum 12V/2A requirements.

4. One green led and one red led - FPGA flashing failed, FPGA might need to be flashed with a FTDI cable.