Some D455 not woring as slave in sync system about librealsense

[MartyG-RealSense]

Hi @FrGrQuim Changing a camera's Inter Cam Sync Mode setting from master to slave should not damage it and it does not sound as though there is damage since it works normally at 15 and 30 Hz.

The ideal situation is if the master is enabled first and the slave(s) secondly afterwards.

Are you changing the camera from master to slave whilst depth streaming is still enabled? If you are, does the problem still occur at 5 Hz if you disable the depth streams, change the Inter Cam Sync Modes and then re-enable the depth streams?

[FrGrQuim]

Hi @MartyG-RealSense, thanks for your response. We always enable the master before the slave, and in our app, we disable the stream before configuring the cameras. (In the RealSense Viewer, it's not possible to change the Inter-Cam Sync Mode when the stream is enabled).

If the issue isn't with the hardware, another hypothesis is that there may be corruption in the persistent memory. I've updated the cameras, so I don't believe it could be from the firmware, but perhaps there's a persistent configuration that causes the cameras to crash under certain conditions. Is there a way to factory reset the camera, not just the calibration parameters?

Also, is there a method to retrieve error codes, logs, or any other type of information that could help us understand why the camera isn't sending frames?

[MartyG-RealSense]

A factory-reset of the calibration creates a new calibration table inside the camera. The camera can not function fully correctly if the calibration table has somehow become corrupted, so writing a new table through a calibration reset can rectify problems caused by a damaged cable. The calibration reset can be performed in the Viewer using the instructions at #10182 (comment)

Also in the Viewer, you can expand open a debug console panel that displays a continuously updating message log by clicking on a small upward-pointing arrow icon in the bottom corner of the Viewer window.

You can set a path on your computer for the log to be sent to a file by clicking on the gear-wheel icon at the top corner of the Viewer window and selecting the Settings option from its drop-down menu, then selecting the General tab on the settings window that pops up and clicking on the box beside 'Output librealsense log to file'.

Select a path on your computer to save the log file to. Finally, click the Apply button on the bottom of the Settings pop-up to confirm the enabling of logging to file.

The link below provides information about accessing other types of logging such as kernel logs.

https://github.com/IntelRealSense/librealsense/blob/master/doc/troubleshooting.md

[FrGrQuim]

I have attempted to factory reset the calibration table of the two cameras, but this didn't resolve the issue. However, when I checked the logs in the RealSense Viewer app, I observed the following logs when I started the depth stream of the slave camera (the master camera's depth stream was already enabled without any error logs):

After that, I encountered the following log that loops indefinitely:

[MartyG-RealSense]

Do the ** Stream Start Failure** and Left IC2 Config Error errors display every time that this particular camera has its depth stream enabled?

'Left IC2 Config Error' is a very rare error that typically indicates that an interposer cable that joins two circuit boards together inside the camera may not be fully seated in its connectors. It is unlikely that there would be a problem with this internal cable though if that particular camera is able to start the depth stream normally most of the time.

[FrGrQuim]

The Left IC2 Config Error occurs each time I initiate the depth stream on this camera under the following conditions:

• The camera is in slave mode
• The stream is set to 5Hz
• The sync cable is connected (with both the master and slave cameras)
• The depth stream of the master camera is enabled

If any of these conditions are not met, I don't encounter the Left IC2 Config Error, and the stream starts correctly. Additionally, if the camera is already stuck in this issue, attempting to restart the stream (even without meeting the aforementioned conditions) will still fail with the Left IC2 Config Error. A hardware reset is necessary to successfully restart the stream.

The occurrence of Stream Start Failure is not consistent, and I haven't identified the specific conditions that trigger it.

[MartyG-RealSense]

There is likely not a physical hardware fault, then.

I would recommend avoiding use of 5 Hz if possible and using a minimum of 15 Hz. At 5 Hz new frames arrive in the frame pipeline slowly enough that the risk of a problem occurring increases compared to 15 Hz and above, where such problems experienced at 5 Hz disappear.

[FrGrQuim]

Okay, so currently, there is no explanation for the root cause of this issue? Is there something we can do to help you understand this problem? Our robot cannot handle 15Hz streams, and even if we limit the rate by requesting a framerate of 5Hz, we still want to keep the camera's framerate consistent with our application.

Additionally, we would like to retrieve the camera logs (similar to the ones available on the RealSense Viewer) directly on the robot. Is there an API that allows us to do this? I tried using the rs2::device::get_info with this parameter:

However, I couldn't find where I can locate the meaning of the debug OP code.

[MartyG-RealSense]

I do not have hardware sync equipment to replicate and test your sync setup, unfortunately.

It may be worth testing to see whether the problem still occurs when using genlock hardware sync. This will involve setting 5 FPS and Inter Cam Sync Mode '1' on your master camera and Inter Cam Sync Mode '4' (instead of 2) on your slave camera, with the slave camera's FPS set to 15 instead of 5. This is because when using a genlock sync mode with a master camera, the slave FPS must be 3x the master FPS. The slave camera will actually operate at the master's 5 FPS, not 15.

If you are programming your own application with script code then a workaround in the past for problems with a particular FPS speed has been to only use every "nth" frame - for example, setting 30 FPS but only using every 6th frame in order to achieve an actual FPS of 5. A RealSense user developed a Python script to demonstrate this principle at #3169 - it sounds as though you are using C++ but the Python script might provide insights about how to implement a similar custom FPS mechanism in C++.

There is not a list of meanings provided by Intel for the debug op codes as the purpose of the logging mechanism was for RealSense end-users to provide the log to Intel so that an Intel RealSense firmware engineer could interpret it.

The RealSense SDK provides a C++ firmware logging tool called rs-fw-logger that provides similar functionality to the RealSense Viewer's firmware log mechanism.

https://github.com/IntelRealSense/librealsense/tree/master/tools/fw-logger

Further information about this logging tool can be found at #1215