NK Technologies, San Jose, CA, has introduced the APN Series power monitoring sensor that measures three phases of current and voltage, and computes 14 values necessary to track power usage in the RS-485 Modbus RTU format. The monitor uses current transformers to measure the amperes. The line voltage connects directly to the transducer, up to 600 VAC. The unit’s RS-485 Modbus RTU format is compatible with many programmable logic controllers, and fits into industrial communications networks, both hard-wired and wireless, depending on the application. It can be configured to accept standard 5-amp current transformer inputs or sensors producing 333 mVAC proportional to the AC current of the circuit. The primary circuit voltage is connected directly to the monitor for 600 VAC or lower, or through a potential transformer for monitoring circuits of higher potentials. The APN is powered from an external supply, and provides a pulse contact to open and close as Watt hours are accumulated.