Detect crossing point
The block accepts one input of type double. If you select the Show output port check box, the block output indicates when the crossing occurs. If the input signal is exactly the value of the offset value after the hit crossing is detected, the block continues to output a value of 1. If the input signals at two adjacent points bracket the offset value (but neither value is exactly equal to the offset), the block outputs a value of 1 at the second time step. If the Show output port check box is not selected, the block ensures that the simulation finds the crossing point but does not generate output. If the input signal is constant and equal to the offset value, the block outputs 1 only if the Hit crossing direction property is set to either.
When the block's Hit crossing direction property is set to either, the block serves as an "Almost Equal" block, useful in working around limitations in finite mathematics and computer precision. Used for these reasons, this block might be more convenient than adding logic to your model to detect this condition.
When the block's Hit crossing direction property is set to either and the model uses a fixed-step solver, the block has the following behavior. If the output signal is 1, the block sets the output signal to 0 at the next time step, unless the input signal equals the offset value.
The Hit Crossing block outputs a signal of type Boolean if Boolean logic signals are enabled (see Implement logic signals as Boolean data (vs. double) ). Otherwise, the block outputs a signal of type double.
The value whose crossing is to be detected.
The direction from which the input signal approaches the hit crossing offset for a crossing to be detected.
If selected, draw an output port.
Select to enable zero-crossing detection. For more information, see Zero-Crossing Detection.
Specify the time interval between samples. To inherit the sample time, set this parameter to -1. See Specify Sample Time in the online documentation for more information.
In the sldemo_hardstop model, the Hit Crossing block is in the Friction Model subsystem.
In the sldemo_clutch model, the Hit Crossing block is in the Friction Mode Logic/Lockup Detection subsystem.