The Emerson VersaMax Micro 4 is the smallest controller in the VersaMax Micro compact PLC family, combining four discrete inputs with built-in analog I/O channels in a single base unit. It targets single-loop control applications — pressure or level regulation, pump alternation, simple alarm monitoring — where a handful of I/O points and analog input suffice and panel footprint is the primary constraint.

Where does the Micro 4 fit in the VersaMax family?

Below the Micro 14, the Micro 4 serves as the absolute entry point — fewer discrete I/O points but with analog input capability built in rather than requiring an expansion module. This makes it a cost-effective choice for OEM machine builders who need one or two analog sensors (4–20mA or 0–10VDC) plus a few discrete inputs for start/stop, limit switch, and alarm sensing, with relay outputs on an expansion module if needed. Up to four expansion modules can be added for additional I/O, following the same VersaMax Micro expansion architecture as the larger controllers.

What programming environment does it use?

The Micro 4 is programmed via Emerson's Machine Edition (VersaMax Pro) software using ladder diagram or instruction list. It supports PID control, floating-point math, subroutines, and Modbus RTU master/slave communication — the same instruction set as the larger Micro models. The compact DIN-rail housing fits into the smallest control panels and machine-mounted junction boxes.