# Stacklight

The stacklight can be configured to display the I/O signals from the controller.

The stacklight can be customized as follows:

- A stack of four lights. One optional light can be added to this stack. You can also customize the order and the color of lights.

- Two positions, A and B, which can be customized with indicator lamps or switches.

- A buzzer placed on the side of the box that has a fixed frequency of 3000 Hz. The buzzer can be configured to activate on any tightening controller signal.

- Two external outputs, two external inputs and a connector for external power.

- Two I/O bus connectors. A termination plug, should be applied to the second I/O bus connector if it is at the end of the I/O bus line. The I/O bus termination plug is listed in the accessory list.