Current-loop measurements

RG terminals can be configured to make analog current measurements using the CurrentSE() instruction. When configured to measure current, terminals each have an internal resistance of 101 Ω in the current measurement loop. The return path of the sensor must be connected directly to the RG terminal. The following image shows a simplified schematic of a current measurement.

Example current-loop measurement connections

The following table shows example schematics for connecting typical current sensors and devices. See also Current-loop measurement specifications.

Sensor type	Connection example
2-wire transmitter using data logger power
2-wire transmitter using external power
3-wire transmitter using data logger power
3-wire transmitter using external power
4-wire transmitter using data logger power
4-wire transmitter using external power