TCP communication, send matrix cut in package, and reconnect the package in the client

Hi,

I create two codes that communicate together through a TCP connexion (one compute, two Matlab instances open). One is the server, the second is the client. My goal is to simulate the recording of signal from an amplifier. The server act as the amplifier, the client as my GUI that record the signal.

In the server I load a data file of signal, which contains 120 channels by XX samples. To simulate the connexion with an amplifier, I use a timer and write every 0.1 second a package of few samples equivalent to the samplifing frequency of the real amplifier (2048 Hz).

This package is a piece of signal cut from the original signal in the function of timer. This package is a matrix of 120 by XXsamples double that I reshape in a 1 by XX samples and turn it in int16 to be written by the server.

The client is running also with a timer, every 0.2 second. The client read in the TCP connexion what is available. So it gets one or more packages reshaped 1 by XX samples int16. Then, I do the opposite operation in the client, turn it back to double and reshape it in a 120 by XXsamples matrix.

My issue is the recomposed signal in the client when plotted doesn't look like the orignal one, and the reason is the concatenation make me losing the orginal package 'orgnisation', when I reshape, I think I'm not reshaping my signal in a good way. And I don't find any answer of how to do it.

Is there a way to send package of signal and to read them and reorganize them correctly ?

You can find below the two codes I did: the server first then the client.

Thank you in advance

%% VIRTUAL AMPLIFIER %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% When opened you can select between different file that will be read in %

% a loop forever, those file of EMG recorded on a participant will be %

% written in a server that the GUI can have access like it was any %

% amplifictor %

close all; clear; clc;

global parameters

signal = load('contraction30sec120channels2048Hz.mat');

fsamp = 2048;

% Timer for Amplifier

parameters.TimerVirtualAmplifier = timer();

parameters.TimerVirtualAmplifier.ExecutionMode = 'fixedRate';

parameters.TimerVirtualAmplifier.Period = 0.01;

parameters.TimerVirtualAmplifier.TimerFcn = @(src,evt) TimerVirtualAmplifierFunction(src,evt); % you can use function handle or an anonymous function.

parameters.data = signal.data;

% 1- Prepare variables for reading in an endless loop the loaded file

parameters.PreviousSize = 1;

parameters.TimeRunning = 0;

parameters.PackageSize = round(parameters.TimerVirtualAmplifier.Period*fsamp);

% 2- Prepare Server

% Find Host Name and Address

% Find the host name and address of the machine where the server is

% created. The client uses this address to connect to the server.

[~,hostname] = system('hostname');

hostname = string(strtrim(hostname));

address = resolvehost(hostname,"address");

% Create Server

% Create the tcpserver object using the address of the machine and port 5000.

% Create a callback function called connectionFcn to write data when a TCP/IP

% client connects to the server. Set the ConnectionChangedFcn property to the

% callback function connectionFcn. You can find the connectionFcn function

% at the end of this example.

try

delete(parameters.server) % In case server haven't been close correctly

catch

end

parameters.server = tcpserver(address,5000,"ConnectionChangedFcn",@connectionFcn);

parameters.server.ByteOrder = 'little-endian';

disp('Server is on')

disp('Waiting for client to connect')

% Start the timer

warning off

%% Callback Functions

% Run the timer to update the data

function TimerVirtualAmplifierFunction(~, ~)

global parameters

newpackageposition = parameters.PreviousSize+parameters.PackageSize;

if newpackageposition > size(parameters.data,1)

package = parameters.data(parameters.PreviousSize:end,:);

parameters.PreviousSize = 1;

else

package = parameters.data(parameters.PreviousSize:parameters.PreviousSize+parameters.PackageSize,:);

parameters.PreviousSize = parameters.PreviousSize+parameters.PackageSize;

end

% Write on server

DataReShapePackage = reshape((package),[],1);

% DataReShapePackage = reshape((package),1,[]);

% Write data only if a TCP Client is connected

if isempty(parameters.server.ClientPort) == 0

DataReShapePackage = int16(DataReShapePackage);

write(parameters.server,DataReShapePackage,"int16");

elseif isempty(parameters.server.ClientPort) == 1

% If the client disconnect (press stop), stop the timer

disp("Client disconnected from the server.")

disp('Waiting for client to reconnect.')

stop(parameters.TimerVirtualAmplifier);

end

end

% Connection Callback Function to Write Binary Data

% This function calls write to write data to the connected TCP/IP client.

function connectionFcn(src, ~)

global parameters

if src.Connected

% If the client is connected, start the timer

disp("Client connection accepted by server.")

start(parameters.TimerVirtualAmplifier);

else

disp("Client not connected to the server.")

end

end

%%%%%%%%%%%%%%%%%%%%% Virtual Amplifier Client %%%%%%%%%%%%%%%%%%%%

close all; clear ; clc

global parameters

%% TIMER %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

parameters.TQuattrocento = timer();

parameters.TQuattrocento.ExecutionMode = 'fixedRate';

parameters.TQuattrocento.Period = 0.2;

parameters.TQuattrocento.TimerFcn = @(src,evt) QuattroncentobackgroundRunningfunction(src,evt); % you can use function handle or an anonymous function.

%% SETTINGS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

parameters.Xlength = 40; % Length of the plot

parameters.EMGGainFactor = 5/2^16/150*1000; %Provide amplitude in mV

parameters.AuxGainFactor = 5/2^16/0.5; % Gain factor to convert Aux Channels in V

parameters.offsetQuattrocento = 50;

parameters.Fsamp = 8; % Codes to set the sampling frequency [0 8 16 24];

parameters.FsampVal = 2048; % Sampling frequency values

parameters.NumChan = 0; % Codes to set the number of channels [0 2 4 6];

parameters.NumChanVal = 72; % Channels numbers

%% TCP Connexion

% Find Host Name and Address

% Find the host name and address of the machine where the server is

% created. The client uses this address to connect to the server.

[~,hostname] = system('hostname');

hostname = string(strtrim(hostname));

parameters.TCPPort = 5000; % Number of TCP socket port

parameters.IP = resolvehost(hostname,"address"); % Virtual amplifier IP adress

parameters.tcpSocket = tcpclient(parameters.IP,parameters.TCPPort, "Timeout",10, "EnableTransferDelay",true);

parameters.tcpSocket.ByteOrder = 'little-endian'; % 'big-endian'

parameters.refreshrate = 1;

parameters.NsampVal = floor(parameters.FsampVal*parameters.TQuattrocento.Period/parameters.refreshrate);

%% Pre allocation

parameters.time = linspace(0, 1, parameters.NsampVal*parameters.Xlength); % this one will be the full time vector for the plot

parameters.signal = (repmat(1:parameters.NumChanVal,parameters.NsampVal*parameters.Xlength,1)) * parameters.offsetQuattrocento;

parameters.PlotChansignalEMG = (0:1:63)* parameters.offsetQuattrocento;

% parameters.PlotChansignalAUX = (0:1:15)* parameters.offsetQuattrocento;

parameters.PlotChansignalAUX = (0:1:1)* parameters.offsetQuattrocento;

parameters.PlotChansignalACESS = (0:1:7)* parameters.offsetQuattrocento;

parameters.temporarymatrix = zeros(round(parameters.FsampVal*parameters.TQuattrocento.Period),parameters.NumChanVal); % in this one the EMG will be stored temporarelly

%% Figure preparation

% parameters.Multiplein(1,:) = 33:96;

% parameters.AUX = 97:112;

% parameters.Accessories = 113:120;

parameters.Multiplein(1,:) = 1:64;

parameters.AUX = 65:66;

parameters.Accessories = 67:72;

parameters.figuresignalQuattrocento = figure(); parameters.figuresignalQuattrocento.Position = [10 400 1700 600];

parameters.axhIN1 = axes('Parent',parameters.figuresignalQuattrocento);parameters.axhIN1.Position = [0.1 0.50 0.8 0.45];

parameters.axhINAUX = axes('Parent',parameters.figuresignalQuattrocento); parameters.axhINAUX.Position = [0.1 0.20 0.8 0.20];

parameters.axhINAcess = axes('Parent',parameters.figuresignalQuattrocento); parameters.axhINAcess.Position = [0.1 0.03 0.8 0.10];

parameters.LineMLTIN1 = line(parameters.axhIN1,parameters.time,parameters.signal(:,parameters.Multiplein(1,:))); title(parameters.axhIN1,'Multiple in 1')

parameters.LineAUX = line(parameters.axhINAUX,parameters.time,parameters.signal(:,parameters.AUX)); title(parameters.axhINAUX,'Auxillary')

parameters.LineAcess = line(parameters.axhINAcess,parameters.time,parameters.signal(:,parameters.Accessories(4))); title(parameters.axhINAcess,'Accessories')

parameters.axhIN1.YLim = [parameters.offsetQuattrocento*-1 parameters.offsetQuattrocento*65];

parameters.axhINAUX.YLim = [parameters.offsetQuattrocento*-0.4 parameters.offsetQuattrocento*18];

parameters.axhINAcess.YLim = [0 parameters.offsetQuattrocento*4];

%% TIMER %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

parameters.i = 0;

DataQuattrocento = fread(parameters.tcpSocket)'; % empty the buffer before starting the function

clear DataQuattrocento

start(parameters.TQuattrocento);

% Wait for user to manually stop the session

uiwait(msgbox('Press OK to stop data acquisition.', 'Stop Acquisition', 'modal'));

%% Stop the DAQ and TCP

stop(parameters.TQuattrocento)

% Close the communication\

flush(parameters.tcpSocket)

delete(parameters.tcpSocket)

clear parameters.tcpSocket

%% Handle function

function QuattroncentobackgroundRunningfunction(src, ~)

tic;

global parameters

parameters.i = parameters.i + 1;

disp(['iteration: ' num2str(parameters.i)])

NumBytesAvailable = parameters.tcpSocket.NumBytesAvailable;

disp(['NumBytesAvailable: ' num2str(NumBytesAvailable)])

Remainder = rem(NumBytesAvailable, 2880);

disp(['Remainder: ' num2str(Remainder)])

NumBytesAvailable = (NumBytesAvailable-Remainder)/2;

disp(['NumBytesAvailableTotal: ' num2str(NumBytesAvailable)])

disp('------------------------------------------------------------')

if NumBytesAvailable <= 0

else

toc

tic

try

DataQuattrocento = read(parameters.tcpSocket, NumBytesAvailable, 'int16')';

% keyboard

toc

tic

DataQuattrocento = reshape((DataQuattrocento),parameters.NumChanVal,[]);

sizedata = size(DataQuattrocento,2);

parameters.NsampVal = ceil(sizedata/parameters.refreshrate);

parameters.refreshedmatrix = DataQuattrocento(:,1:parameters.refreshrate:end); % Apply downscale if necessary

parameters.signal(1+parameters.NsampVal:end,1:parameters.NumChanVal) =...

parameters.signal(1:end-parameters.NsampVal,1:parameters.NumChanVal);

parameters.signal(1:parameters.NsampVal,1:parameters.NumChanVal) = parameters.refreshedmatrix';

% Multiple in 1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Ysignal{1} = ((parameters.signal(:,parameters.Multiplein(1,:))*parameters.EMGGainFactor)+parameters.PlotChansignalEMG)';

Ysignalmultiplein1 = num2cell(Ysignal{1},2);

set(parameters.LineMLTIN1, {'YData'}, Ysignalmultiplein1)

% Aux %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Ysignal{2} = (parameters.signal(:,parameters.AUX)+parameters.PlotChansignalAUX)';

YsignalAUX = num2cell(Ysignal{2},2);

set(parameters.LineAUX, {'YData'}, YsignalAUX)

% Accessories %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Ysignal{3} = (parameters.signal(:,parameters.Accessories(4))+parameters.PlotChansignalACESS(:,4))';

YsignalAccess = num2cell(Ysignal{3},2);

set(parameters.LineAcess, {'YData'}, YsignalAccess)

clear DataQuattrocento

tcpserverfind

catch

keyboard

end

toc

end

end

[Animesh]

Hey @Mikael Jonathan, can you attach the "contraction30sec120channels2048Hz.mat" file?

[Mikael Jonathan]

Hi @Animesh, thank you for your interest in my issue.

Here is a like to the file:

https://www.transfernow.net/dl/20240827Q8x6kCKS

Or I linked a smaller version were I reduced the number of samples (to be below the limit of the 5mb)

Answer 1

[Sivsankar]

Hi Mikael,

You have mentioned that the package signal is a matrix of 120 by XX samples. But the provided mat file is of the format XX by 120. So, I believe that the discrepancy that you are facing is because of the package you are sending.

In the server code make the following change:

DataReShapePackage = reshape(package', [], 1); % Transpose to get [120, XX] and then reshape

Transposing the package matrix would make the signal a 120 by XX matrix. This is the output that I’ve obtained by making the following change:

I believe this is the desired output. Hope this helps!

[Mikael Jonathan]

Hi @Sivsankar, you indeed found the solution, I just did several trials, it was this transposition that I missed. Thank you very much !