How to use 'Circle to Finite Line Force Enabled' input

[Clyde92]

I'm wondering if you can instruct me on how to use the input for the aforementioned block? the Help button just pipes me to the normal block (Circle to Finite Line Force), which doesn't describe the additional input function.

I've tried a step function into the input but received the following error:

The signal connected to the input port of "contact_1/Circle to Finite Line Force Enabled/Bus Selector1" is not a bus signal. The input to the Bus Selector block must be a virtual or nonvirtual bus signal. A possible cause of this error is the use of a bus-capable block (such as Merge or Unit Delay) that in this current situation is unable to propagate the bus downstream to the block reported in this error. Please see Simulink documentation for further information on composite (i.e. bus) signals and their proper usage.

MATLAB/Simulink: 2020a
Library: 20.1.5.1`

[Clyde92]

I figured out I needed to use a bus creator and name the signal vy. However for my system, as soon as the step function goes high giving the enable signal my thing flips out!

I'm trying to make an object pass through another on the way up and then land on the other side. So I'm enabling it just after it passes the other side of the finite line.