Question about serialport() vs serial() on different versions on Matlab

I am trying to communicate with a HIOKI LCR device. I have a sample program from HIOKI a part of the code is attached.

Now this program is written in Matlab version 2019a, I have version 2023b.

It works fine on older Matlab version(I tested it on matlab 2019b), but there is no communication with the HIOKI on the newest version of Matlab. I know that from version 2019b serial is being replaced with serialport. So i have tried altering the code.

% (0)Class variable

properties (Access = public)

SerialPort = ''; % Serial Port Device

MsgBuf = ''; % Received Data

ReceiveTimeout = 0; % Receive-Timeout [ms]

end

properties (Access = private)

ofs = 0; %Description

end

methods (Access = public)

% (1)Connect

function ret = OpenInterface(app,port,speed,timeout)

ret = false;

try

clear app.SerialPort

app.ReceiveTimeout = timeout;

app.SerialPort = serial(port); % Create a serial port object/Set the COM port

app.SerialPort.timeout = timeout;

set(app.SerialPort,'BaudRate',speed); % Set communication speed

set(app.SerialPort,'Terminator','CR/LF'); % Set the terminator

app.SerialPort.InputBufferSize = 1E6;

fopen(app.SerialPort); % Open the serial port

app.SendButton.Enable = true; % Enable the Transmit button

app.Timeout.Editable = false; % Uneditable after the connection is established

app.COM.Editable = false;

app.Speed.Editable = false;

ret = true;

catch

msgbox ("Err_OpenInterface")

ret = false;

end

end

% (2) Disconnect

function ret = CloseInterface(app)

ret = false;

try

fclose(app.SerialPort); % Close the serial port

delete(app.SerialPort) % Dump the serial port object

clear app.SerialPort

app.SendButton.Enable = false; % Disable the Transmit button

app.Timeout.Editable = true; % Editable after disconnection

app.COM.Editable = true;

app.Speed.Editable = true;

ret = true;

catch

msgbox ("Err_CloseInterface")

ret = false;

end

end

% (3)Send commands

function ret = SendMsg(app, strMsg)

ret = false;

try

strMsg = (strMsg); % Add a terminator, CR+LR, to transmitted commands: Additional settings are not required since terminator characters have already been set

fprintf(app.SerialPort, strMsg); % Write data in the transmit buffer

ret = true;

catch

msgbox ("Err_SendMsg")

ret = false;

end

end

% (4)Receive

function ret = ReceiveMsg(app, timeout)

ret = false;

app.MsgBuf = ""; % Clear received data

tic; % Start a stopwatch

try

% Continue the loop until LF is received

while(1)

rcv = fscanf(app.SerialPort); % Read data from the receive buffer

if ~isempty(rcv)

rcv = strrep(char(rcv),char(uint8(13)),""); % Delete CR in received data

if strfind(rcv,uint8(10)) > 0 % End the loop when LF is received

buf = char(rcv);

rcv = buf(1:strfind(rcv,uint8(10)) - 1); % Extract data without LF and the following from the original received data

app.MsgBuf = strcat(app.MsgBuf,rcv); % Save the data

break

else

app.MsgBuf = [app.MsgBuf rcv]; % Save the data

end

end

ew = toc; % Get elapsed time

if ew > timeout

app.MsgBuf = "Timeout";

MsgBox (app.MsgBuf)

return

end

end

ret = true;

catch

msgbox ("Err_ReceiveMsg")

ret = false;

end

end

% (5)Transmit and receive commands

function ret = SendQueryMsg(app, strMsg, timeout)

ret = false;

ret = SendMsg(app, strMsg); % Transmit commands

if ret

ret = ReceiveMsg(app, timeout); % Receive response when command transmission is succeeded

end

end

end

I changed the orignal code that uses the old serial() functions to this (i used this: https://nl.mathworks.com/help/matlab/import_export/transition-your-code-to-serialport-interface.html#mw_61890a86-a984-4f4d-9800-edb569a585b8 to help me):

function ret = OpenInterface(app,port,speed,timeout)

ret = false;

try

app.ReceiveTimeout = timeout;

app.SerialPort = serialport(port,speed); % Create a serial port object/Set the COM port

configureTerminator(app.SerialPort,"CR/LF") % Set communication speed

% Set the terminator

app.SendButton.Enable = true; % Enable the Transmit button

app.Timeout.Editable = false; % Uneditable after the connection is established

app.COM.Editable = false;

app.Speed.Editable = false;

ret = true;

catch

msgbox ("Err_OpenInterface")

ret = false;

end

end

......

% Continue the loop until LF is received

while(1)

rcv = readline(app.SerialPort);

if ~isempty(rcv)

rcv = strrep(char(rcv),char(uint8(13)),""); % Delete CR in received data

if strfind(rcv,uint8(10)) > 0

I have 2 questions:

1)Why does the original code not work in newer versions of Matlab?

2)Are the alterations I did correct to be compatible with serialport() instead of serial()?

Answer 1

[Shivam Lahoti]

Hi Sebastiaan,

I can see the 'serial' object is not recomended as mentioned in the following documentation:

https://www.mathworks.com/help/matlab/ref/serial.html

The steps taken be you are logical. Below is a detailed answer for your queries:

1) Why does the original code not work in newer versions of MATLAB?

Although the `serial` object was not deprecated in MATLAB R2019b, it was marked as not recommended for use, with the introduction of the `serialport` object offering a more modern and efficient interface for serial communication. The `serialport` object provides enhanced performance and additional features, necessitating modifications to existing code that uses the older `serial` object. While `serial` is still available in versions after R2019b, transitioning to `serialport` is advisable for improved functionality and future compatibility.

2) Are the alterations I did correct to be compatible with serialport() instead of serial()?

Your modifications are mostly correct, but a few adjustments can enhance compatibility and performance. When using the 'serialport' object, it's important to note that the 'Timeout' property is specified in seconds, unlike the previous serial object, which used milliseconds, so you should adjust the timeout value accordingly. Additionally, the 'readline' function in 'serialport' simplifies data reading by automatically reading until it encounters a line terminator, eliminating the need for manual terminator handling as required in older implementations. Furthermore, implementing proper error handling is essential to catch any issues during serial communication, ensuring the robustness of your application.

I hope this helps clarify your query.

Regards,

Shivam.