Obviously you are using the Generic-App.
What you are doing is correct. Currently you can only command either position or velocity (not at the same time).
Velocity setpoints are integrated to a position command. This happens in root/Control/jointJogIntegrators/. These are integrators with limiters on the inputs and outputs. So make sure your limits are setup correctly for your application.
Once the signal is a position command this is fed into PVA-Limiters. These smooth and limit the signal. You can find the settings of the PVA limiter in the Desk tool.
Here you can set for instance the maximum velocity and acceleration.