Arcade Drive in Autonomous mode and Tank Drive in Teleop mode?
 

In Labview, can we keep the Autonomous code as provided, which uses Arcade Drive & 2 motors, but in Teleop mode, use Tank Drive to drive 4 motors?

Re: Arcade Drive in Autonomous mode and Tank Drive in Teleop mode?
 

Simple answer: yes.

The number of motors is actually set in Begin when the drive motors are opened. The default project uses Open 2 Motor Drive. You can replace that with Open 4 Motor Drive.

Once you've done that, any of the drive functions will control it appropriately. Arcade Drive and Tank Drive do exactly what they should. (If you've built a holonomic drivebase with mecanum or angled omniwheels, Holonomic Drive will work too.)