Ethernet & 4-20 mA Transmitter for AC Phase Angle & Power Factor

Transmits phase angle and power factor of AC waveforms. DIN Rail mounted, digitally programmable.

Ethernet transmitter


  • Ethernet Serial Data I/O, Modbus TCP or TDM ASCII protocol
  • 4-20 mA, 0-20 mA or 0-10V transmitter output, 16 bits, jumper selectable, isolated
  • Dual 120 mA solid state relays for alarm or control, isolated
  • 5V, 10V or 24V dc transducer excitation output, isolated
  • Transmits phase angle between two AC wave shapes of similar period
  • Transmits power factor from 1.000 to 0.000 with sinusoidal signals
  • For frequencies from 0.005 Hz to 10 kHz, voltages from 10 mV to 250 Vac
  • Phase angle resolution of 1°, 0.° or 0.01°, accuracy of 0.03% at AC line frequency
  • Analog output resolution 0.0015% of span (16 bits), accuracy ±0.02% of span
  • Universal AC power, 85-264 Vac, or low voltage power, 10-48 Vdc or 12-32 Vac

Phase Angle Measurement

Phase angle measurement by digital phase meter

Phase angle in degrees indicates the phase lead or lag between two periodic signals of the same period, as determined from their zero crossings. These two signals will typically be the voltage and current applied to a load. As illustrated, the phase angle in degrees is +360*P1/P.

The phase angle transmitter transmits the lead or lag in degrees from 0° to 360° between two periodic signals of the same period. In the illustration to the right, phase angle is 360*P1/P. The signals are applied to the Channel A and B inputs of the dual-channel pulse input signal conditioner board. A resolution of 1°, 0.1° or 0.01° is selectable. Accuracy is 0.01% up to 100 Hz, 0.1% at 1 kHz, and 1% at 10 kHz.

Power Factor Measurement

The power factor of an AC power system is the ratio of real power in watts (W) divided by apparent power in volt-amperes (VA). For sinusoidal signals, power factor is the cosine of phase angle.

The power factor transmitter computes power factor as the cosine of phase angle. Power factor readings can range from 1.000 to 0.000 with three decimal places and an accuracy of 0.1% for sinusoidal signals at 50/60 Hz power line frequency. While power factor is always positive, the meter artificially assigns a minus sign to power factor for negative phase angles, and it sets power factor to 0 for phase angles greater than 90°.

Designed for flexibility

Signal conditioner board used with  Phase Transmitter

Phase angle and power factor are determined by timing crystal clock pulses over a specified gate time which is selectable from 10 ms to 199.99 s. By selecting the minimum gate time of 10 ms, the update rate can be up to 20/s for 50/60 Hz AC line frequency. Improved accuracy is obtained by making the gate time long enough so that multiple cycles can be averaged.

Exceptional Accuracy and Stability. transmitters determine frequency by taking the inverse of period as measured with a calibrated quartz crystal time base. This results in extremely accurate and stable 6-digit internal readings (±999,999 counts), which are then processed in software. The analog output is generated by an ultra-linear 16-bit (65,536 step) digital-to-analog converter (DAC) for 0.02% output accuracy. The update rate of the transmitter output is a programmed gate time + 30 ms + 0-2 signal periods. For a 60 Hz signal, the update rate would be 20 per second. Such fast update rates are ideal for alarm and control.

Standard features of LTE transmitters include:

  • Ethernet I/O, isolated. Supported protocols are Modbus RTU and ASCII (tunneled via Modbus TCP) and TDM ASCII. The latter is simpler than the Modbus protocol and is recommended when all devices are s. Note that RS232 or RS485 data I/O in lieu of Ethernet is provided by 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 -99,999 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.

Discovery and configuration of Ethernet Nodes is easily achieved with TDM's Node Manager Software, and the discovered transmitters can then be programmed using TDM's Instrument Setup Software. Both softwares run on a PC under MS Windows and can be downloaded from this website at no charge.

 Ethernet network by TD Micronic
Phase Angle Mode
Item Transmitted Phase angle difference between two waves of same period
Transmitted Units 1°, 0.1°, 0.01°
Frequency Range .005 Hz to 10 kHz
Resution .01°, .005 Hz to 100 Hz, 0.1° at 1 kHz, 1° at 10 kHz
Accuracy 0.03° at 50 or 60 Hz
Maximum Timing Interval 200 sec
Power Factor Mode
Item Transmitted Power factor between two sine waves of same period
Transmitted Units 1.000 to 0.000, 1.00 to 0.00, or 1.0 to 1.0
Polarity Negative sign indicates negative phase angle
Frequency Range 0.005 Hz to 10 kHz
Accuracy 0.1% at power line frequencies
Signal Types Sinusoidal AC and square waves
Signal Ranges 10 mV to 250 Vac
Signal Ground Common ground for channels A & B
Noise Filter 1 MHz, 30 kHz, 250 Hz (selectable)
Update Rate
Conversion Interval Gate time + 30 ms + 0-2 signal periods
Gate Time Selectable 10 ms to 199.99 s
Time Before Zero Output Selectable 10 ms to 199.99 s
Analog Output (standard)
Output Levels 0-20 mA or 0-10 Vdc (selectable)
Compliance, 4-20 mA 10V (0-500 ohm load)
Compliance, 0-10V 2 mA ( kOhm load)
Output Resolution 16 bits (65,536 steps)
Output Accuracy 0.02% of output span plus conversion accuracy
Output Isolation 250V rms working, 2.3 kV rms per 1 minute test
Ethernet Data I/O (standard)
Type 10/100 Base-T Ethernet per IEEE 802.3
Data Rates 300, 600, 1200, 2400, 4800, 9600, 19200 baud
Output Isolation 250V rms working, 2.3 kV rms per 1 min test
Serial Protocols Modbus TCP, Modbus RTU, Modbus ASCII, TDM ASCII
Modbus Compliance Modbus over Serial Line Specification V1.0 (2002)
Digital Addresses 247 for Modbus, 31 for TDM ASCII
Dual Relay Output (standard)
Relay Type Two solid state relays, SPST, normally open, Form A
Load Rating 120 mA at 140 Vac or 180 Vdc
Sensor Excitation Output (Standard)
Output levels 5V@100 mA, 10V@120 mA, 24V@50 mA (jumper selectable)
Output Isolation 50V from signal ground
Power Input
Standard Power 85-264 Vac or 90-300 Vdc
Low Power Option 10-48 Vdc or 12-32 Vac
Power Frequency DC or 47-63 Hz
Power Isolation 250V rms working, 2.3 kV rms per 1 min test
Power Consumption 2W typical, 3W with max excitation output
Dimensions 129 x 104 x 22.5 mm case
Mounting 35 mm rail per DIN EN 50022
Electrical Connections Plug-in screw-clamp connectors
Operating temperature 0°C to 55°C
Storage temperature. -40°C to 85°C
Relative humidity 95% at 40°C, non-condensing
Cooling Required Mount transmitters with ventilation holes at top and bottom. Leave 6 mm (1/4") between transmitters, or force air with a fan.
Ethernet & 4-20 mA Output Transmitter for Phase Angle and Power Factor
LTE Ethernet Transmitter Pinout
Application Example
Using Meters, Counters or Transmitters to Synchronize Motor Generators
Using  Meters, Counters or Transmitters to Synchronize Motor Generators
Synchronization of two motor generators requires that the two frequencies be identical, that the lines be in phase, and that the line voltages be close to each other. In this illustration, a single dual channel counter (or frequency transmitter) measures both frequencies to six-figure accuracy in a few line cycles. Another dual channel counter (or phase transmitter) measures phase angle to 0.1° resolution. Two AC RMS Voltmeters, which offer ranges of 200.00 V and 600.0 V, are used to display the two RMS voltage to 0.1% accuracy.

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