RS232 communication script fails

[j.wagner96]

Hi All!

to communicate with pumps in a test rig, I use a RS232 bricklet. Communication seems alright when I use BrickViewer and was already able to send commands and recieve data (see image).

As future communication should be run by a MATLAB script, I tried sending the same command in the following code (derived from the RS232 Bricklet Example), which did not work at all. 

clear
clc
import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletRS232V2;
import java.lang.String;

HOST = 'localhost';
PORT = 4223;
UID = 'MyUID'; % Change XYZ to the UID of your RS232 Bricklet 2.0

ipcon = IPConnection(); % Create IP connection
rs232 = BrickletRS232V2(UID, ipcon); % Create device object
ipcon.connect(HOST, PORT); % Connect to brickd

rs232.disableReadCallback();
rs232.write(String('OUT_SP_1 100').toCharArray());
ipcon.disconnect();

I also tried adding \r\n to the char, which also did not work. Can you tell, where my fault is? 

bearbeitet April 30, 2025 at 15:16 von j.wagner96

[photron]

Try this.

clear
clc
import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletRS232V2;
import java.lang.String;

HOST = 'localhost';
PORT = 4223;
UID = 'MyUID'; % Change XYZ to the UID of your RS232 Bricklet 2.0

ipcon = IPConnection(); % Create IP connection
rs232 = BrickletRS232V2(UID, ipcon); % Create device object
ipcon.connect(HOST, PORT); % Connect to brickd

% make sure the Bricklet has the expected configuration
rs232.setConfiguration(9600, BrickletRS232V2.PARITY_NONE, BrickletRS232V2.STOPBITS_1, BrickletRS232V2.WORDLENGTH_8, BrickletRS232V2.FLOWCONTROL_OFF);

rs232.disableReadCallback();
rs232.write(String('OUT_SP_1 100\r\n').toCharArray());
ipcon.disconnect();

[j.wagner96]

Thanks for your help! Manually setting the configuration sadly didn't have an effect and the device does not react to any commands sent by the matlab script.

bearbeitet May 2, 2025 at 11:10 von j.wagner96

[photron]

It seems in MATLAB "\r\n" doesn't produce the CR and LF characters you're looking for.

Try this:

rs232.write(String('OUT_SP_1 100' + char(13) + char(10)).toCharArray());

 

[j.wagner96]

That seems right, but there's still no reaction of the device. 

 

EDIT: Found the error.

Instead of adding the CR and LF like in your advice

rs232.write(String('OUT_SP_1 100' + char(13) + char(10)).toCharArray());

, concatenate it like so: 

rs232.write(String(['OUT_SP_1 100' char(13) char(10)]).toCharArray());

that worked - at least - for me.

bearbeitet May 2, 2025 at 11:41 von j.wagner96