THe JUMO dTRON 3xx controller series consists of 4 user programmable devices in various DIN formats to control temperatures, pressures, and other process variables. The devices are used as temperature controllers TR according to DIN EN 14 597 in heat generating plants for the control of temperatures in fluid and gas mediums. The high-contrast, multicolor LCD display for the actual value, setpoint value, and operator guidance consists of 2 four-digit seven-segment displays, 2 single-digit 16-segment displays, display of active setpoint values, 6 relay status indications, and displays for unit, ramp function, and manual mode. Simple operation with 4 keys. The devices can be used as two-state, three-state, three-step controllers, or continuous controllers. Among other things, the controller software includes 1 program or ramp function, 1 parameter block switch, 2 autotuning procedures, 1 math and logic module, and 4 limit value monitors. The linearizations of the common measuring probes are stored; programming of a customer-specific linearization table is possible. A setup program is available for easy-to-use configuration on a PC. The devices can be integrated in a data network through a RS422/485 or PROFIBUS DP interface. The electrical connection is made at the back with screw terminals. The block diagram displays the possible input and output configurations. The option boards are universally applicable for all devices in the series.