The only part of the electronics package that isn't integrated into the main circuit board is the daughterboard component, which is housed in the bottom of the breech section. This small circuit board houses the anti-chop eye components, which includes the infrared LED, phototransistor, and a pair of resistors. The daugherboard is connected to the mainboard using a four-point wire harness (commonly known as the wire harness). The daughterboard is C-shaped and wraps around the bottom of the breech section, and is easily slid out of position for removal and cleaning.
When installed, the C-shaped circuit board fits within the Ion breech section.
When removed, the daughterboard looks like this:
Vision System Performance: 
The eye system used on the Ion is a type of beam-break anti-chop eye, which describes an pair of eyes that emit and receive the signal, respectively. This type of eye system is quite reliable and easy to use. The only time you will experience issues with the eye functioning or not is when the wire harness or eyes themselves are damaged (which is usually easy to visually notice). The stock board is programmed without any complex eye buffers or other subroutines, so the purchase of some aftermarket boards may improve the performance of the system even further. Moreover, aftermarket boards include much more advanced eye programming which is able to more accurately track the movement of the eye from shot to shot (known as eye validation). Please refer to the mainboards’ page for a list of aftermarket boards.
Overview:
· Ions come stock with beam-break eyes.
· The eye components are housed on a daughterboard in the breech section.
· A lenght of wires connect the two boards.
Related Links:
· Main circuit board
· Vision troubleshooting