LLRP yo tcp

[tcccruz]

Hello, could you help me? I get the code to work fine.
But I would like to make a server socket at the same time to output the tag id and its arrival time via TCP.
And at the same time and go recording a csv all those tags

Thank very much.

Jose Cruz

[esitarski]

Hi Jose, pyllrp is a low-level library for communicating with LLRP readers. It is possible to do what you want, but the library doesn't do it build-in. You will need to do some work with threads and queues to put it together. In CrossMgr, I do something similar in https://github.com/esitarski/CrossMgr/blob/master/CrossMgrImpinj/Impinj.py, which you can use as a reference for writing your own code. For your application, you need to do something like this: - Connect to the LLRP reader using a python thread. See ImpinjServer in Impinj.py. In this thread function, what is most important is the dataQ where the thread writes the tags onto a python queue. messageQ, strayQ and shutdownQ are used for sending status messages, stray tags, and shutdown control respectively (check the code). In my code I need a messageQ as I can't write to the terminal, I have special processing to determine stray tags (written to strayQ), and I use shutdownQ to send a message to shutdown the thread gracefully. You probably don't need all of this, so simplify as required. - From the thread, open the socket and put the reader into the mode where each tag read is transmitted as soon as it is received (you don't want to constantly query it). In Impinj.py, this is done with a call to GetBasicAddRospecMessage (in pyllrp) when FirstReadMethod is used. - Your thread is now fully dedicated to monitoring the reader socket and timestamping the arrival time (as you want). - It then "puts" the tag and arrival timestamp onto a python queue. In Impinj.pyu, this is done in reportTag. You want to do this as soon as possible so the socket does not fill up, and so you get the most accurate arrival timestamp for the tags. Note that the tags have a read time given to them from the reader, and the reader may send multiple tags all together in a batch. - So far so good. You now have a dedicated thread that monitors the reader socket, adds the arrival time, and writes the results to a queue. - You then need to write another thread that processes the dataQ, In your example, this thread write the tag and arrival timestamp via TCP and records it in a csv file. - The reason you want two threads and a queue is that you don't want any TCP or file latency to compromise your ability to get accurate arrival times. By using two threads, any delays that happen in your TCP/.csv thread won't affect your reader loop. - The GIL is not a factor here as both threads will be blocked on IO most of the time. IO blocks release the GIL, so everything will run smoothly. You also have to make some decisions about how you want to handle multiple reads. If a tag is parked next to the reader, it will be read continuously. GetBasidAddRespecMessage (in pyullrp.py) has an ROReportSpec_Parameter specifying Timeout=500, which means that if a tag is read multiple times in 500 milliseconds, it will be reported as one read only. Consider if you need to make your own version of this function with a different Timeout length. I hope the explanation and sample code helps.

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On Thu, Feb 20, 2025 at 5:00 PM tcccruz ***@***.***> wrote: Hello, could you help me? I get the code to work fine. But I would like to make a server socket at the same time to output the tag id and its arrival time via TCP. And at the same time and go recording a csv all those tags Thank very much. Jose Cruz — Reply to this email directly, view it on GitHub <#7>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AABGXKNKZ2OOJWPR22FIWIT2QZGA3AVCNFSM6AAAAABXR2L6CSVHI2DSMVQWIX3LMV43ASLTON2WKOZSHA3DOMZWGUYDINY> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***> [image: tcccruz]*tcccruz* created an issue (esitarski/pyllrp#7) <#7> Hello, could you help me? I get the code to work fine. But I would like to make a server socket at the same time to output the tag id and its arrival time via TCP. And at the same time and go recording a csv all those tags Thank very much. Jose Cruz — Reply to this email directly, view it on GitHub <#7>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AABGXKNKZ2OOJWPR22FIWIT2QZGA3AVCNFSM6AAAAABXR2L6CSVHI2DSMVQWIX3LMV43ASLTON2WKOZSHA3DOMZWGUYDINY> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

-- Edward Sitarski

[tcccruz]

Hello, thanks for the reply, I have it working now and everything is ok, the only problem is that I use the tornado example and I get a speed of about 6 Tags per second and instead the impinjtest application must be about 325000 per second.