API for 2 scanners

[bazzou-mohammed]

Hi, I am currently working on a LIDAR detection project and using a Sick LMS511-10100. By following a tutorial on Windows without ROS, I successfully retrieved data from my scanner. Now, I would like to incorporate another Sick LMS511-10100 and integrate them both into a single API. Is it possible to achieve this? If so, could you please share any tips or tricks you have used to accomplish this? Thank you for your help.

[rostest]

Thank you for your feedback. Currently the API does not support concurrent processing of multiple lidars. You may run each lidar in a separate process using the sick_scan_xd API and interprocess communication. We recommend using ROS-1 or ROS-2 to run multiple lidars. See https://github.com/SICKAG/sick_scan_xd/issues/169 for further information.

[bazzou-mohammed]

Hi, Thank you for the feedback, the problem we're having today is that we can't use the ROS-1 and ROS-2 processes because they don't suit our environment. do you have another issue. Thank you for your help.

[bazzou-mohammed]

Hi, I'd like your advice on using a single API for 2 scanners. I remind you that I work with two Sick LMS511-10100 scanner, on Windows and without ROS. If I follow these steps, do you think I will be able to process two scanners simultaneously :

• Initialize two separate instances of the connection object using the "sick_scan_xd" API. For example, create two connection objects named "scanner1" and "scanner2" to represent the two Lidar scanners respectively.
• Configure each scanner individually using the methods provided by the "sick_scan_xd" API. This may include operations such as configuring measurement parameters, and repeat these steps for each scanner instance.
• Start the measurement for each scanner by calling the appropriate "sick_scan_xd" API methods for each scanner instance. For example, call the initialization methods for "scanner1" and "scanner2" respectively.
• retrieve data from each scanner individually from events or streams provided by the "sick_scan_xd" API. Thank you for your help.

[rostest]

Thank you for your feedback. Processing 2 or more lidars concurrently with multiple calls of SickScanApiInit-functions requires threadsafe libraries. The sick_scan_xd library is currently not guaranteed to be fully thread-safe. Processing 2 lidars this way can cause unexpected results incl. core dumps.

Currently you can run 2 lidars in 2 different processes, where each process runs one lidar using the SickScan-API functions. In this case, the integration of both processes in a single application requires interprocess communication and data exchange.

[gigades]

@rostest Just curious. I saw that SickScanApiInit() return a handle that have to be passed to other functions. It seems like you have designed it to support multiple scanners in the first place. What made you change your mind? I have the same requirements and using inter-process communication to communicate with multiple scanners make the development unnecessarily complicate.