2-wire mode

In this mode, the control inputs are internally 'pulled up' to +5V DC via a 4.7kOhm resistor. Therefore, no external voltage source is needed to create contact closure to ground (for switches such as mute buttons) or resistance to ground (for other multi-state or continuous controls such as Parameter Presets or faders).  

BLU-80/BLU-800/BLU-100 Series

The diagram below shows connections for an external switch, resistor ladder and potentiometer.  Two 'common' ground connections are provided using the 2 'C' pins to the left of the control inputs.

Table of resistor values for use with Parameter Presets or source selectors.

A 47kOhm-log potentiometer connected between a control input and common will allow parameters to be controlled linearly.