I'm sending udp packets from a device to my pc.
Proof: (click here to enlarge)
I'm using the standard "UDP Receiver VI" from LabVIEW (labview\examples\comm\UDP.llb)
But the data I sent is not displaying on the vi, even though you can see that I'm sending the UDP packet.
Please help
Labview program:
(enlarge)
Without any LabVIEW code it's hard to see what's going wrong.
Here's a working exapmle of a sender and receiver in one VI:
Could it be that you have multiple ethernet ports on your system?
Perhaps is setting the net address on the UDP open connection an option.
You have spotted the port on the front panel (64100) is not the same as the port you are sending data to (64000) ?
Related
I am working on Windows with C# but this is more of a general question.
If I receive UDP packages with a UDP client they are normally removed from the receive buffer so other programs can no logner access this data.
My experiments showed that this is not the case for boradcast messages. If I connect multible programs to the same UDP port and call the receive function both application can see the broadcast packages, but only one application can see unicast packages as they are deleted when first read by the OS?? I guess...?
My question is is there a way to change this socket behaviour? can I set up my socket to preserve this data so a second programm could access it as well? Or is this not possible?
the overall goeal as you can guess is to have multible programs receive the same UDP packagees send via Unicast.
After alot of research i can confirm this is not possible with unicast packages.
You can use PCAP to achive this but not with the native UdpClient
I’m really new on the coding world and I need your help. I need to do the following:
In a Zedboard platform I take data from a USB port and want to make real time packets and send them via TCP.
I have establish FreeRTOS for that. I take the data from a UART and keep them in a cycle buffer. I send a TCP command from Matlab for starting the transmission but that gives me just one packet of data. How a make this real time?
I'm afraid I don't understand your question - you mention both USB and UART - is the USB a virtual COM port? Whether its a UART of a USB port, once the received data is placed in the buffer you can use something like a direct to task notification to unblock a higher priority task to then send that data over the TCP link.
There is a FreeRTOS/Zynq/TCP example on the following link: http://www.freertos.org/FreeRTOS-Plus/FreeRTOS_Plus_TCP/TCPIP_FAT_Examples_Xilinx_Zynq.html
I have a software which uses a TUN device to read datapackets, process something on them and send them out. Now I am asking myself, if it is possible, to send the "tun packets" without touching them.
Over the TUN device I get IP Packets but over a RAW socket I just can send self defined transport layer packets...
Is there a possibility to just take this packet from the TUN device and send it over a network card out?
If anybody is interested in that topic, I wrote a witepaper to wrap up all needed information to use RAW-sockets: http://tuprints.ulb.tu-darmstadt.de/6243/1/TR-18.pdf
You didn't enable IP_HDRINCL socket option on the RAW socket?
If IP_HDRINCL option is enabled, you can send self defined network layer packets.
I have an Arduino Uno R3 with an Arduino WiFi shield. The WiFi shield has the most current firmware (V1.1.0). I am trying to send a packet to the router that is about 900 bytes (the packet is for setting up a UPnP port map). This packet is stored in program memory to conserve SRAM. Using strcat_P, I can pull the packet from memory into a buffer and send it using the WiFiClient library (TCP).
The problem is that I can't send the whole packet. For testing, I just send the packet to my computer located on the same LAN where I use a packet sniffer to view the packet. Using WiFiClient.write(), I get differing performance depending on the size of the buffer I use. I seem to get the best performance calling WiFiClient.write() with a buffer size of 80 repeatedly until the whole packet has been "sent". Anything greater than about 80 will cause blank packets on the other end. However, with 80, I usually only see about 500 bytes get transmitted. The packet always gets cut off at an arbitrary point. Does anyone know what could be causing this?
I've did a lot of Googling, and I see others having similar problems. I have never ran across a solution, though.
I know this is old, but I recently found this article which addresses the issue you are describing.
tl;dr - You can only write 90 bytes at a time to the wifi shield's buffer
So I know how to broadcast a packet on the LAN (send it to x.x.x.255) IP. I am confused on how to receive the packet on the receiving host. Like i don't know what kind of socket connection I need to use. Please help me. Thanks
You need to use UDP sockets. At receiving side just keep on listening like any normal UDP socket. No special setup is needed.