TORQUE CONTROL

[Gualty]

Is possible, with a PCI7344, change between velocity and torque control ?
In my application I must move the my axis at contact of the object with a programmable force, then i must do a programmable movement without force control. My servo drive have a torque control imput (0 -> 10V) or can use the velocity input (0 -> 10V) as torque control, with a digital input to select the mode.

[Brent_R]

Yes, this is possible with the PCI-7344. You can leave the servo drive in torque mode for all moves and use the controller to specify torque. For the first part of the move, set the torque limit to the desired value. Once the first move is done, disable all axes momentarily, change the torque limit to its maximum value, re-enable the axes, and continue with the second move in position control mode. This will give you the force control you are looking for.

Regards,

Brent R.
Applications Engineer
National Instruments

[Gualty]

Thank You Brent for your answer, I have only another question: when I execute a move with a torque limit, the PCI-7344 don't generate an error ? I have an error between the command position and the real position of the axis.

[Brent_R]

You will need to assure that the position of the system does not get behind by more than the maximum allowable following error. For the constant torque portion of your profile, try using a sequence of blended moves, with each move being less than the allowable following error (use 30k counts or so). This should eliminate the possibility of getting a following error. With blending, the sequence of short moves will appear like one continuous move.

Regards,

Brent R.
Applications Engineer
National Instruments