The DRR450 thermoregulator has been designed to control temperature and current on multizone systems via RS485 communication standard and Modbus RTU/Slave protocol. It is extremely compact and features direct plug-in connection to the mono-phase SSR power module, reducing wiring costs and installation time. The integrated current transformer allows monitoring of current on the load and management of the relative alarm. In addition to SSR control output, a second output is available on the controller and it is programmable for alarms or heating/cooling PID functions.