Curve Tool: Auto Repeat Curves

The Auto Repeat feature affects what happens when the end of a curve is reached. Auto Repeat is available only for Enhanced curves. See Standard vs. Enhanced Curves for details. With respect to Auto Repeat, Standard curves behave the same as an Enhanced curve with Auto Repeat disabled. The behaviors with and without Auto Repeat are described below:

Auto Repeat Disabled:

When the last point in a curve is reached, the axis will stop and hold position at the final curve point. The In Position bit will turn on once the Actual Position comes within the In Position window from the Target Position. The curve will no longer be followed, even if the curve was geared to a master axis and the master axis goes backward.

If the curve is geared to a master axis and the master axis goes backward beyond the first point in the curve, the axis will hold position at the first point in the curve. If the master axis goes forward again, then the curve will begin to be followed from the start. The In Position bit will never come on in this situation because the curve is not completed.

Auto Repeat Enabled:

When the axis reaches either end of the curve, it will automatically continue at the other end of the curve. There will be no position discontinuities, as described below.

Offset Positions on an Auto Repeat

When a curve wraps around from the start to end or vice versa, the positions of the first and last points in the curve are compared. If they are equal, then the curve continues without further event. If they are not equal, then the RMC offsets the position of the axis by the difference between the first and last points' positions. This offset is only allowed on axes with rotary feedback devices such as quadrature and rotary SSI. Attempting to auto repeat a curve with different start and end positions on an axis with a linear feedback device such as MDT, Analog, or linear SSI will fail with a parameter error.

To enable or disable Auto Repeat for a curve:

On the Tools menu, click Options.
Click the General tab.
Find the check box on the row of the axis you want to change under the column labeled Auto Repeat. To enable Auto Repeat, set this check box. To disable Auto Repeat, clear this check box.
Click OK.