The EZ-ZONE RM controller simplifies thermal system management. The EZ-ZONE RM integrated controller family is comprised of six module types: an integrated on-off or PID control, monitoring and over/under temperature limit controller module, a high-density on-off or PID control module, a high-density limit-only module, an input/output (I/O) expansion module, a high-density monitor/scanner module and a data logging and field communications access module. A system is configured by connecting any combination of module types to address specific application needs. The EZ-ZONE RM is extremely flexible and scalable allowing mixing and matching of I/O to configure 1 to 152 control loops and up to 256 monitor points.