CODEWITHSUNDEEP
node-redplctemperature
homeiq
homeiq

Reputation: 1

PT100 RTD with WISE 4012E in Node-RED

I have a pt100 sensor which is connected to RTD transmitter with 0 to 5v output, temperature -50 to 300*c, input voltage 24v. I have connected the temperature sensor with transmitter to Advantech WISE 4012E (PLC) analog input and i get the values in node red as voltage. How to convert that voltage into temperature and help me with the code.

Upvotes: 0

Views: 531

Answers (1)

SteveR
SteveR

Reputation: 1131

This is more of a sensor question, than node-red... but if you do as suggested and measure the voltages of ice water and boiling water, you can extrapolate the temperature easily without any code -- just wire in a range node with those two data points defined (V0 Volts @ 0°C, and V100 Volts @ 100°C). Of course, if your elevation is very far from sea level, you will also have to adjust for the local boiling point temperature, as well.

Assuming the output is linear, the output of the range node will be the approximate temperature. You may want to check the spec sheet for your device to determine the usable range of voltage readings, and clamp the readings -- but for most home automation projects, this will not be an issue.

For a far more scientific explanation of how to use your PT100 to measure temperatures, there are lots of resources online, such as this instructable by Roboro.

Upvotes: 1

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