Explanation of the USB RTD Input Module

USB Analog and Digital IO Modules

LucidControl USB IO Modules

  • Data acquisition and control

  • Cost effective and flexible

  • Platform independent

  • Windows® and Linux

  • Compatible with RPi and Beagle Bone

  • Clippable on DIN-Rail

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  • Industrial & home automation

USB Digital Input Module

USB Digital Input Module

LucidControl Product Series

  • 4 digital inputs

  • 3 voltage level options

  • Opto insulated contacts

  • Counters and edge detectors

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USB Digital Output Module

USB Digital Output Module

LucidControl Product Series

  • Opto insulated option

  • 4 digital outputs

  • Relay module option

  • Pulse width modulation and timers

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  • Switching and power control applications

USB Analog Input Module

USB Analog Input Module

LucidControl Product Series

  • Measurement range options

  • 4 analog inputs

  • e.g. 0 ~ 10 V or -10 ~ 10 V

  • 14 bit resolution

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  • Acquisition of sensor signals

USB Analog Output Module

USB Analog Output Module

LucidControl Product Series

  • 4 analog outputs

  • Output range options

  • e.g. 0 – 10 V or 4 – 20 mA

  • 12 bit resolution

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  • 4 – 20 mA current interfaces

USB RTD Input Module

USB RTD Input Module

LucidControl Product Series

  • 4 Pt1000 / Pt100 RTD inputs

  • Temperature range: -180 ~ 180 °C

  • 0.1 °C resolution

  • Heat control applications

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  • Logging of temperatures



The LucidControl USB IO Module Product family provides a USB RTD input module ready to measure the temperatures of 4 Pt1000 sensor elements. A typical application of the USB RTD module is a USB temperature logger.

RTD Input Module Principle of Two-Terminal Sensing

USB RTD Measurement

The RT4 USB RTD Input Module is able to measure temperatures of -180°C to +180°C with a resolution of 0.1°C and an accuracy of +/- 0.5°C over the entire measurement range.

The temperature measurement device measures the resistance of a RTD by performing a two-terminal measurement as it is used by standard in order to determine a resistance by using two probes. Compared to three-terminal sensing or four-terminal sensing, the principle of the LucidControl RT4 USB RTD Input Module does disregard errors on the connection cables of the sensor element. This method is a good compromise between cost and accuracy and allows the connection of standard Pt1000 elements.

The picture on the left hand side shows the typical connection of a Pt1000 element. The RT4 USB temperature measurement device processes the 4 sensor element subsequently. The activated element is sources with a constant current IM which flows through the RTD Rt. This constant current causes a voltage UM across the RTD Rt which is proportional to the resistance and (nearly) proportional to the environment temperature of the RTD. This voltage is amplified and measured with a resolution of 14 bits and as a result the value of the resistance is calculated.

If the measured resistance it outside of defined borders, the USB temperature measurement devices are able to detect if a sensor element is working properly of e.g. if the connection cable has a short circuit or the cable is broken.

After the measurement has been performed, the USB RTD Input Module continues in a cycle manner.

For further questions about the USB RTD temperature measurement device or any other module of the LucidControl Product Series, feel free to contact us.