080G0321 by Danfoss

The 080G0321 is a programmable controller produced by Danfoss within the MCX Programmable Controllers series. It is intended to execute application-specific logic for HVAC and refrigeration skids, coordinating compressor banks, evaporator fans, and auxiliary loads from a single embedded platform. By merging sensing, calculation, and actuation in one DIN-rail package, the unit streamlines panel wiring and supports networked supervision through its native MODBUS port. This arrangement allows the controller to react quickly to changing operating conditions and manage routine sequences without a separate industrial PC.

The hardware platform provides 8 analog inputs for probes such as pressure transducers or NTC temperature sensors, while separate 8 digital inputs accept contact closures from float switches or door sensors. Control commands are issued on 8 digital outputs, which share a cumulative current limit of 32 A, and DO5 and DO6 each require a minimum load of 50 mA, permitting direct control of solenoid valves or small contactors. Power is supplied at 230 V AC, and the board draws only 20 VA, so heat dissipation remains low inside compact control cabinets. With the logic engine able to stage up to eight compressors and select from two analog outputs, the device supports balanced load distribution and capacity modulation while maintaining noncondensing operation at relative humidity levels up to 90 percent. This mix of input and output channels supports common refrigeration tasks such as safety monitoring, compressor staging, and response to external interlocks.

The unit provides 2 analog outputs for inverter speed reference or valve position signals, and it has an enclosure rated IP20 that is suitable for protected indoor panels. Synchronization with mains supplies is universal because the power section accepts line frequencies of 50/60 Hz. Reliable performance is maintained over a broad service window from -20 °C to 60 °C, allowing the controller to be mounted in rooftop units or cold rooms without additional conditioning. The MODBUS channel enables setpoint updates, alarm reporting, and data logging from supervisory SCADA or BMS hosts, which supports integration with larger control networks.