Hello Raimundas,
Yes, you can communicate with a host/master via a serial port using MODBUS ASCII/RTU in MATLAB, even when your MATLAB code is running on a slave device. Although MATLAB's built-in functions are more straightforward for TCP/IP communication, you can still achieve serial communication by using MATLAB's 'serialport' function. Here's a general approach to setting up MODBUS ASCII/RTU communication in MATLAB:
% Initialize serial port for MODBUS ASCII/RTU communication
port = "COM3";
baudRate = 9600;
s = serialport(port, baudRate);
% Configure serial port parameters
configureTerminator(s, "CR/LF"); % Use CR/LF for MODBUS ASCII
s.DataBits = 8;
s.Parity = "none"; % adjust if needed
s.StopBits = 1;
% Function to process MODBUS requests
function response = processModbusRequest(request)
% Parse the request and generate a response
% Implement your MODBUS logic here
% Example: Echo back the request as a response
response = strcat("Response: ", request);
end
% Main loop to wait for requests and respond
while true
if s.NumBytesAvailable > 0
request = readline(s); % Read incoming request
response = processModbusRequest(request); % Process request
writeline(s, response); % Send response to master
end
pause(0.1); % Pause to prevent CPU overload
end
- Modify the 'processModbusRequest' function to implement your specific MODBUS logic.
- The script continuously checks for incoming data and processes it in real-time.
- Consider adding error handling for production code to manage unexpected data or communication issues.
This script provides a basic framework for MODBUS ASCII/RTU communication on a slave device using MATLAB. Adjust the code as necessary to fit your specific application and protocol requirements.
Hope this helps!
