Receive, Read and Interpret the Bytes Received via UDP Packets

Hello Everyone,

I have two nodes connected and continously communicating via UDP Sockets.

I tried with fscanf(udp) and fread commands but I got the following error: "Warning: Unsuccessful read: The specified amount of data was not returned within the Timeout period."

I changed the DatagramTerminateMode to be off. Do I have to set the buffer size or any other property, and if yes then how? I would really appreciate any help.

Regards

[Walter Roberson]

How large are your packets and how quickly are they being sent? Are you sending termination characters with the packets?

[PTP]

Hello Walter,

on First laptop PTP daemon is running which sends packets continously to the another laptop where I want to receive these. Messages are normally 86 bytes on Wire and are sent with a very high frequency which means i receive 1000 of packets in a short time. I have confirmed it by Wireshark software.

I also tried using callback functions if at all I am able to receive and read the packets sent.

My mainM file

u1 = udp('192.168.2.10',320,'LocalPort',320);

u1.InputBufferSize = 1024;

u1.DatagramTerminateMode = 'on';

u1.DatagramReceivedFcn = {@callback_u1};

fopen(u1);

My callback_u1 function file

function output = callback_u1(obj, event)

disp('data received')

[data,count,errmsg] = fread(u1,64,'uchar');

But sometimes nothing happens at all as if no packets are received which is not true and sometimes i get *error messages like:

data received undefined function or variable 'u1'

Error in callback_u1(line 4)

Error in instrcb(line 36)

Warning: The DataReceivedFcn is being disabled. To enable the callback property either connect to the hardware with FOPEN or set the DataReceivedFcn property.*

I still do not know what I am doing wrong. Everything seems to be in place. Only i am not able to read the packets in Matlab. Please help me with this.

Kind regards

[PTP]

Here is the wireshark file that I have attached and also the errors: