Cube Soft Limit Parameters

There are plenty of methods of creating interference zones and axis limits on a Yaskawa robot controller. Some of these methods are directly tied into an internal safety circuit (function safety unit) and some are not safety-rated but are still effective in not allowing a robot to enter a certain unsafe area or cause damage to itself due to external structures and EOAT. One of those methods includes cube soft limit parameters.

By default, a Yaskawa robot has a predefined envelope of motion based on its mechanical links and limitations. However, based on an application, it is not always desirable to have the robot utilize its full range of motion to prevent collision with other robots and external structures. Cube soft limits can help with limiting your robot’s working envelope.

To enable cube soft limits, first make sure your Security Mode is set to MANAGEMENT MODE. Then, under the Parameter tab, navigate to the S2C parameters and go to S2C0001. Each bit in this parameter allows you to enable the cube soft limit check for up to 8 robots that are linked together (ie. DR2C).

After cube soft limit check has been enabled, navigate to the S3C parameters and start with S3C0000. Each of these cube limits correspond to the base coordinates of the active robot TCP and must be formatted in micrometers (µm). For example, if the robot needs to stop moving at X=455.5mm in the positive X-direction and X= -375mm in the negative X-direction, then the value 455500 would be entered into S3C0000 and the value 375000 would be entered into S3C0003. If a cube limit is not needed or is irrelevant to the application, then simply type all +/- 9’s into that parameter.

Once the cube soft limits are set, once a robot reaches that base coordinate limit, it will automatically stop and an error message will appear on the bottom of the pendant screen.

This is a very straightforward and simple method to limiting the working envelope of a robot, but if a more robust and complex interference method is required and there is no functional safety unit (FSU) enabled on the robot controller, please refer to the following Knowledge Center article to learn more about the Interference Function.