Velocity vs torque mode

What are the advantages/disadvantages of both of these operating modes for a servo system?

What is recommended?

Normally velocity mode is suggested as its easier to tune and doesn't need high update rates

Torque mode is appropriate where you need to know the motor load

Velocity mode, (or when the velocity loop is closed by the drive, and the control sends a velocity command to the drive for movment) is usually much simpler to tune, and is less resource demanding for the control.

Torque mode, (velocity loop is closed in the control, the drive is mostly just a dumb amp and the control sends a torque (or current) signal to command a movement) much trickier to tune, and often requires a much faster servo thread speed to get good results.

For the most part if your drives offer both you'll want to choose velocity mode.