The Target is a block from the OpenBlocks mod. This block is used to create a redstone signal, with the strength based on how close to center an arrow is shot. There are three parts of the Target: blue, red, and yellow.
The Target is only able to operate if it has a constant redstone signal, if it does not, it will fall down into idle mode. When this redstone signal that keeps the Target upright goes away, all arrows attached to it will drop on the floor.
The Target's signal strength is determined by the location of the arrow in relation to the bulls-eye. In determining the strength to output, it uses the following mathematical formula: where is the distance between the arrow's location and the bulls-eye. In layman's terms, the strength can be broken down as following.
|Color||Approximate redstone travel strength in blocks|