Modbus 485 RTU converter

Modbus 485 RTU converter

EKO MODBUS 485 RTU Converter
EKO Sense Software


  • Universal MODBUS 485 RTU Converter
  • For Solar Sensors, PT-100, NTC 10kΩ
  • Up to 100 units in parrallel
  • Easy menu settings
  • Advanced sensor temperature correction and linearity functions
  • IP65 All weather enclosure
  • Optional USB contoller and EKO sense control software to change settings
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The MODBUS 485 RTU converter called "M-Box" is a digital signal conditioner to convert the Voltage output of a solar radiation sensor, PT-100 or 10kΩ NTC temperature sensor into a MODBUS 485 RTU output. The converter can be used with all passive EKO radiometers or any other mV sensor to be connected to data loggers or inverters with a MODBUS 485 RTU input channel. By using the signal conditioner the sensor cable can be easily extended over long distances without any signal loss or potential electromagnetic interference in noisy industrial environments. With MODBUS up to 100 different sensors and converter units can be addressed and connected in parallel.

The mV signal of the solar sensor will be converted to irradiance 0 - 1600 W/m2. In this case the sensitivity factor of the solar sensor will be set to the converter. With the optional USB controller and EKO Sense software (Multiple languages) the converter settings can be freely changed. This tool will be needed in case the sensor sensitivity might need to be changed after a periodical solar sensor re-calibration.

For practical installation, the converter is placed in an IP65 Aluminium box with universal cable glands. It has robust input/output screw terminals, which can be easily connected to the signal cable that leads to the measurements system at the installation site. EKO can pre-connect the solar sensor cable to simplify your process.




Input Range

DC 0 to 100mV


Digital (Modbus)



Input Impedance


Temperature Response (-20~50℃)

< 0.2%

Accuracy Assured Operating Temperature Range

-20 to +50℃

Operating Humidity Range

≦ 95RH% (no condensation)

Response Time

1sec. (99% Output)


< 0.1% (0-100mV)

Zero Offset

<5μV (Output offset value when 0mV is input @ 140Ω)

Power Supply Voltage Conversion Error

<0.05% (When supply voltage changed from 12V to 24V)

Power Supply

DC 12~24 V ±20%

Power Consumption



φ45 × 27.1mm



Aluminium box

IP 65

 Dimensions Box

80 x 125 x 57 / Cable gland M12 (ø3-6mm)


Download 3D

(Google SketchUp)