Can't read UDP packets

[CarlosSp]

Hi everyone. I'm triying to read the UDP packets that a board with a CPU and ethernet module is sending me via ethernet connection. In the board I've just implemented a static IP+UDP packet that only needs to change the data in order to send a temperature that the board measures. The packets are sent well and I can see them with a sniffer software like Wireshark like UDP packets with all the IP's, MACs and that stuff. The problem is that in Labview I'm not capable to read that data, even I can't read anything. I tried the UDP open + UDP read specifiying the destination port (40056 in my case).

Any help please???

Although, I wanted to ask if the destination IP is strictly necessary if you specify the MAC adress.

Thank you

[Ben]

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@CarlosSp wrote:

Hi everyone. I'm triying to read the UDP packets that a board with a CPU and ethernet module is sending me via ethernet connection. In the board I've just implemented a static IP+UDP packet that only needs to change the data in order to send a temperature that the board measures. The packets are sent well and I can see them with a sniffer software like Wireshark like UDP packets with all the IP's, MACs and that stuff. The problem is that in Labview I'm not capable to read that data, even I can't read anything. I tried the UDP open + UDP read specifiying the destination port (40056 in my case).

Any help please???

Although, I wanted to ask if the destination IP is strictly necessary if you specify the MAC adress.

Thank you

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Please post the code you are working with.

A pictue is worth a thousand words in LV.

Ben

[CarlosSp]

OK, I'll put a picture of the LV code (it's pretty simple, I just want to see the data). And also I'll put a picture of wireshark to see that I receive the UDP packets.

[CarlosSp]

still having troubles, anyone?

[JorgeNakan]

Hola,

Ya probaste los ejemplos "UDP Receiver" y "UDP Multicast Receiver" ?. 

Hace tiempo trabajé con comunicación UDP, tuve un problema similar en donde no recibía datos.  Me acuerdo haber modificado uno de esos ejemplos y la comunicación empezó a funcionar perfectamente.

Jorge N.

[CarlosSp]

Gracias pero ya lo solucioné 🙂 El problema era que en el Wireshark me decia que el Checksum UDP estaba desactivado y me daba todas las tramas por buenas. Yo pensaba entonces que le checksum UDP no hacia falta y no es así. El LabView o el Windows me filtraba estas tramas como malas y las desechaba por lo que probé con un dato constante, por lo que le checksum también era constante y funcionó todo perfecto. Por lo que ahora en vez de un paquete estático me estoy mirando una librería que implemente la capa TCP/IP y que incluya UDP. He encontrado el lwIP pero de momento no me aclaro mucho con las APIs que tengo que usar.. :P Saludos