icinterface.fopen cannot bind

I want to test a UDP module on a fpga board which should send data to a machine running Matlab through a ethernet cable.

I wrote the following script and test it between two machine running matlab, it works. In short, the script opens a udp object and print to screen each data it receives.

However, when I plug the ethernet cable to the machine and the board, running the script I got an error using icinterface.fopen: "it cannot bind" ( I presume it cannot assign the port or the ip address).

Assuming the worst scenario in which the udp module on the board does not work, I do not see why matlab should not be able to create a udp "listener". Udp do not require any syncronization or reply.

Any idea on what exaclty icinterface.fopen does? Why it cannot associate the port/address?

Here's the main script

ip_listener = '192.168.0.3'; % IP current machine
port_listener = hex2dec('6af0'); % port current machine
ip_source = '192.168.0.1'; % IP board
port_source =hex2dec('6aef'); % port board

nBytes = 5; 

      udp_listener = udp(ip_source, port_source, ...
      'LocalPort', port_listener,'LocalHost', ip_listener);

      udp_listener.BytesAvailableFcnCount = nBytes;
      udp_listener.DatagramTerminateMode = 'off';
      udp_listener.BytesAvailableFcnMode = 'byte';
      udp_listener.BytesAvailableFcn = {'showBytes', nBytes};

      fopen(udp_listener)

      udp_listener.RecordDetail = 'compact';
      udp_listener.RecordMode = 'append';
      udp_listener.RecordName = [folder '\buffer_bytes.bin'];
      record(udp_listener,'on') % save

% to close
%     record(udp_listener,'off'); fclose(udp_listener)

which also requires this function

function showBytes(obj, event, n)
transpose(fread(obj,n))

Answer 1

[Nick]

fopen requires the ethernet port to be physically connected via cable with a POWER ON machine. Doing so, the code runs.