Delta’s Basic DI/DO Relay Multifunction Power Meter DPM-C501L is designed as a 3-phase high-precision smart power meter that fulfills the demand for monitoring the electricity data of multi-factories, and is suitable for installation on electric panels. ? Measures electric parameters and harmonics ? Supports alert and parameter group settings ? Adopts the MODBUS protocol, suitable for control system applications, SCADA systems, and energy management & monitoring systems ? Adopts 4 DI / 2DO ports