The UCS-221E sequencer control module - two stage from Kele is a solid-state device used for multistage control in HVAC systems, sequencing boilers or chillers. The module also sequences floating/tri-state control of VAV boxes from a single analog signal for building automation systems, BAS. The UCS-221E can be used to obtain a digital output from a voltage or current producing sensor. Units may be daisy chained to provide additional stages of control, and a mounting track is supplied for easy installation.