The UMX-8 multi-function input/output expander is a unique microcomputer-based multifunction interface that expands the input or output capability of building automation controllers. It has eight SPDT output relays that provide on/off control from a jumper-selectable PWM, current or voltage input signal. The sequence of operation can be easily selected by DIP switches. A dual mode allows two UMX-8s to be controlled in sequence from a single input signal. The HOA switch allows for manual override of each relay output. Feedback and LED's provide status indication of the UMX-8. The UMX-4 provides four SPDT output relays. All jumper positions and DIP switch settings are identical to the UMX-8. The operation of the UMX-4 is identical to relays 1-4 on the UMX-8. Feedback and LED's provide status indication of the UMX-4.