Ethernet & 4-20 mA Transmitter for AC RMS Voltage or Current

The Laureate AC RMS input transmitter and signal conditioner provides six voltage input ranges and four current input ranges, all factory calibrated and jumper selectable. A special 5.000A range utilizes a built-in 0.01 ohm shunt to accept the output of 5A current transformers, with no need for a stepdown transformer. The current readings can easily be scaled digitally as needed. High common mode rejection allows stable readings with current shunts located on the high side of the line. Digital filtering is selectable for noisy signals.

True RMS precision circuitry is used to determine the root-mean-square of complex waveforms from DC to 5 kHz. Spikes up to 3.0 times the maximum of each range are accurately measured.

Accuracy is 0.03% of full scale for the transmitters with 1 Megohm input resistance, signals from DC to 5 kHz, and signal amplitude down to 0. The crest factor (Vp / Vrms) is 3.0 at full scale, increasing to 300 for a signal amplitude of 1% of full scale. A version with 10 Megohm input resistance is available as a factory special, but decreases the maximum frequency from 5 kHz to 1 kHz for three of the voltage ranges.

True RMS readings in as little as one 50/60 Hz AC line cycle are unmatched in the industry. Such a high read rate allows anomalies to be detected and alarmed before they become expensive problems. On/off control and alarm can be achieved dual solid state relays, which are standard. Transmitter can also capture peak and valley for times as short as one 50/60 Hz AC power line cycle.

Standard features of Laureate LTE transmitters and signal conditioners include:

• Ethernet I/O, isolated. The supported protocols are Modbus RTU and ASCII, which are tunneled via Modbus TCP. Note that RS232 or RS485 data I/O is provided by Laurel's LT Series transmitters.
• 4-20 mA, 0-20 mA or 0-10V analog transmitter output, isolated, jumper-selectable and user scalable. All selections provide 16-bit (0.0015%) resolution of output span and 0.02% output accuracy of a reading from 0 to 99,999 counts that is also transmitted digitally. Output isolation from signal and power grounds eliminates potential ground loop problems. The supply can drive 20 mA into a 500 ohm (or lower) load for 10V compliance, or 10V into a 5K ohm (or higher) load for 2 mA compliance.
• Dual solid state relays, isolated. Available for local alarm or control. Rated 120 mA at 130 Vac or 180 Vdc.
• Universal 85-264 Vac power. Low-voltage 10-48 Vdc or 12-32 Vac power is optional.
• AC or DC coupling is jumper selectable. AC coupling is suitable for applications such as measuring the ripple on a DC power supply. Multiple integral cycles are averaged for signals above 50/60 Hz. A single cycle is captured for signals from 3 Hz to 50/60 Hz. Below 3 Hz and at DC, the capture rate is every 333 ms.

Node discovery and configuration of Laureate Ethernet transmitters are easily achieved with Laurel's Windows based Instrument Setup Software. Additional features are provided by Laurel's Windows based Node Manager Software, such as the ability to send emails or test messages either periodically or in the event of an alarm. Both softwares run on a PC under MS Windows, are at no charge, and can be downloaded from this website.