Send data to Programmable Power supply from Arduino by RS232
First you will need a TTL to RS-232 adaptor. These are most commonly known as the &quot;MAX232&quot; and is available as a little module.
This will convert the 0-5V TTL signal the Arudino produces into the ±10V signal that RS-232 uses. There's plenty of tutorials online about how to use them.
Then you need to generate the signal. Yes, for the Arduino UNO the SoftwareSerial library is what you want.  Again there's plenty of tutorials on using it.
To actually send the instructions it may be something like:
#include &lt;SoftwareSerial.h&gt;

SoftwareSerial PSU(10, 11); // RX, TX

void setup() {
    PSU.begin(9600);
}

void loop() {
    for (int i = 0; i &lt; 11000; i += 100) { // I'm working in millivolts here.
        PSU.print(&quot;VSET1:&quot;);
        PSU.println(i / 1000.0, 2); // Convert millivolts into volts with 2 DP
        delay(10); // 10ms delay
    }
}

I haven't tested it, but that should give you 0-11v rising at 0.1v per 10ms.