Scientific automation: high measurement accuracy over a large frequency range
The new EL3773 power monitoring terminal for the Beckhoff EtherCAT I/O system is designed to monitor the condition of a three-phase AC or a DC mains network. It collects instantaneous values of power and voltage at an extremely fast sampling rate of up to 10,000 samples/sec and makes them available to the higher-level PC controller for calculation or analysis. The input channels are transferred via oversampling; this results in the acquisition of actual values with a significantly higher resolution in terms of time than the communication cycle time.
The EtherCAT distributed clocks method is used as the basis for the highly precise acquisition of measured values in the EtherCAT Terminal system. These distributed clocks synchronise the EtherCAT devices with very high precision, independently of the PLC cycle. The EL3773 EtherCAT Terminal measures voltage and current via three channels in each case. The six channels are measured simultaneously based on the EtherCAT oversampling principle with a temporal resolution of up to 100 μs and passed on to the controller. The maximum sampling frequency for each channel is 10 kHz.
On the basis of the data supplied, it is possible with the aid of a PC to calculate true RMS values, power, power factors and frequency, and complex user-specific algorithms via the voltage and current curves. The fast sampling rate also enables the measurement of voltage and current peaks. Using the EL3773 power monitoring terminal, interference can be detected and corrected promptly in order to avoid damage to devices, increased electricity costs and downtime and to optimally boost the productivity of manufacturing facilities.