Configuring a Current Input


How to connect and configure current inputs to a UI module?

Product Line

SmartStruxure Solution


UI-16, UI8-DO-FC-4, UI8-AO-4, UI-8/AO-V-4


How are Current inputs configured?


The Technical Reference guide defines the internal resistor for measuring current inputs ("I/O Modules Deep Technical reference") as 47 Ohm.

No additional external resistors are required, the internal resistor is automatically put into the circuit by selecting "Current Input" when creating the software point, there are no DIP switches to change as in some other products.

An external Power supply will be required to provide the current in the circuit through the sensor and into the UI input. 24V DC supplies are usually used to power the sensor & provide the current drive.

Example Circuit:

The input point configuration allows you to define the top and bottom or the current scale (usually 4-20mA or 0-20mA) and the engineering units this corresponds to i.e. 0-100% or 0 - 400 DegC.

The following screen shot example shows the configuration for a 4-20mA input signal represented as 0-100%