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Find out how to connect a sensor with 4-20 milliamps output to a Datalogger/PLC






Possible wiring setups
Sensor and datalogger/PLC input channel have the same number of wires (2 or 3)
Just cable the sensor to the datalogger/PLC as per instructions.
2-cable sensor, 1-cable datalogger input channel
Refer to the diagram below.

2-cable sensor, 3-cable datalogger/PLC input channel
Refer to the diagram below.

3-cable sensor, 2-cable datalogger/PLC input channel

Possible case setups
Once the sensor is connected to the datalogger with an input in electrical current, it is necessary to enter the calibration data. The purpose of this page is to help the operator enter the correct data required in any possible situation.The datalogger requires OFFSET and GAIN
The range values are provided by the sensor data sheet. The application will calculate the required Slope Gain and Offset factors. OFFSET is the value of slip with respect to the reference value indicated by the manufacturer and GAIN (also called SLOPE) is the ratio between the range scale of the actual parameter measured by the sensor and the parameter of electrical current indicated by the manufacturer.
Example:

Datalogger configuration requires BEGINNING OF SCALE and FULL SCALE values
Enter the values from the sensor data sheet operation ranges. BEGINNING SCALE=enter the values at the lower end of the range indicated by the manufacturer. FULL SCALE=enter the values at the upper end of the range indicated by the manufacturer.
Example:

Datalogger configuration doesn’t allow current values in (mA) because they are out of limit but indicated in sensor data sheet
You need to obtain the value corresponding to the 4mA and 20mA starting from the sensor data sheet.
Example:

The system requires a calibration with different values of the range the scale
You need to find the value in (mA) corresponding to the new parameter.