Universal measuring transducer
with Ethernet interface
with HTTP, TCP/IP, Modbus-TCP protocol 2 limit value or pulsed outputs
Universal measuring transducer with Ethernet interface with HTTP, TCP/IP, Modbus-TCP protocol 2 limit value or pulsed outputs
The measuring transducer Multi-E-MU serves to measure current, voltage, frequency, active and reactive power, apparent power and the power factor in case of sinusoidal quantities. The measurement is possible in alternating current systems and 3-wire or 4-wire threephase power systems with same or any load.
The 29 measurands may be displayed, stored and configured via a 10 Mbit/sec Ethernet LAN interface at the PC. Up to 13000 series of measured values may be stored in the internal memory of the measuring transducer. Furthermore, the measuring results may be displayed via web browser or be read and further processed via HTTP, TCP/IP or Modbus-TCP protocol. Two further outputs may be used as limit value or pulsed outputs. The switching status of the limit value or pulsed outputs is indicated by 2 LEDs.
The parameters to be measured are transmitted to a 22 bit A/D converter with a sample rate of >20 kSPS via a current and voltage transformer. In a microcontroller, the required values for the outputs are calculated from the measured parameters. The output values for current and voltage are rms-values. The frequency is calculated from the period of the voltage signal of phase L1. The active powers are calculated from the products of the samples of current and voltage of the three phases. The calculations of the reactive power of the three phases are done using the product of the samples of the currents and the 90° offset voltage signals. The apparent power is the sum of the products from the three rms-values of current and voltage. The power factors are calculated from the apparent power values and the active power values.
The two limit value and pulsed outputs are galvanically isolated from all inputs and the auxiliary voltage. An auxiliary voltage is required.