Controlling of sabertooth driver.

Hi I am new to arduino programming and I want to control 2 motors with sabertooth driver in DIP switch position (1 3 and 5 on) simplified serial mode and arduino mega.

   Serial.println("first loop motor1");
  ST1[0].motor(1, 10);
    Serial.println("first loop motor 1");
  ST1[0].motor(1, 0);

Can anybody let me know what is the meaning of (1,10) and what will happen if I make it (2,10)
and for making the wheel rotate reverse I changed the values to (1,-10) but when I upload both wheels will turn so I am unable to understand how this code works is it because of the garbage values from arduino mega.
Can anybody please help with the rotating of motors independently and removing of garbage values.

SharedLine.ino (1.54 KB)

Sabertooth2x12.pdf (1.31 MB)

It looks like to documentation says that STl[0].motor(1,10); means you are setting the power to 10 for the M1 driver. If you change the '1' to '2' then you are talking to M2