Feed to Length

The Feed to Length instruction is used for point to point moves. If you just want to move the motor a fixed number of steps, this is the instruction to use. When you click on the Feed to Length button in the Program Line... dialog box, you'll see the Feed to Length dialog box appear. This is where you enter the parameters for the move.

Decel - this is the rate at which the drive decelerates to a stop at the end of the move. It's also the rate at which the motor reduces speed if you choose that option. The range is the same as for acceleration. Because friction encourages a motor to stop, you can usually set decel higher than accel.

Distance - this is the number of motor steps you want to move. The maximum number is 16,000,000.

Direction - you can choose cw or ccw as the direction for the move. Just dot the appropriate circle by clicking on it.

Speed - this is the maximum speed you want the motor to go, in revolutions per second. You can set the speed anywhere between .025 and 50 rev/sec, in increments of .025 rev/sec. You can also reduce speed during the move by checking the box marked "Reduce speed during move." This is useful for applications where a tool may need to approach a work piece quickly, but slow down just before making contact.

Analysis - Click on this tab to see a speed vs time graph of your move. It also provides some useful statistics about the move, such as the duration of the move and the portion of time spent accelerating and decelerating. You can also select a plot of speed vs distance.

Accel - stepper motors cannot achieve a high speed instantly. The indexer-drive must gradually accelerate the motor to speed. The rate at which you can accelerate depends on the inertia of the motor and load, the torque available from the motor, and how fast you want it to go. You may need to experiment to find this out. The PSMCC1 has an acceleration range of 1 to 3000 revs/sec/sec.