An interface is disclosed. The interface can include a single node that can be configured to receive a state signal and a serial communication signal. The interface can also include a switch circuit and a switch control circuit, where the switch control circuit is capable of being influenced by the receipt of the state signal or the serial communication signal at the single node and can set the state of the switch circuit based on the receipt of the state signal. Additionally, a switch buffer circuit is coupled between the switch and the switch control circuit, where the switch buffer circuit is configured to prevent the serial communication signal from activating the switch circuit. As such, both the state signal and the serial communication signal can be transmitted over a single node without adversely affecting the operation of pre-existing components.