Sinking vs. Sourcing

The terms sinking and sourcing are used in the Motion Engineering Slice I/O part description. If you are unfamiliar with these terms, take a minute and read this guideline.

With those two guidelines in mind, let's take a look at how they apply to inputs and outputs.

Sinking Input

In an input slice, the terminology describes what the slice does with the current from the load. In a "sinking" slice, it "sinks" current to ground. You will need to supply the voltage rail for the load.

Let's look at a simple diagram of how to wire a switch to a sinking input. Notice that you switch a positive voltage to the slice, which "sinks" current to ground.

Sourcing Input

In an output slice, the terminology describes what the slice does with the current from the load. In a "sourcing" slice, it "sources" current to the voltage rail. You will need to supply the ground for the load.

Let's look at a simple diagram of how you would wire a switch to a sourcing input. Notice that you switch the ground connection to the slice, which "sources" it from the voltage rail.

Sinking Output

In an output slice, the terminology describes what the slice does with the current from the load. In a "sinking" slice, the slice "sinks" current to ground. You will need to supply the voltage rail for the load.

MEI has digital inputs for 5, 12-24, or 48 volts. You will need to choose a slice for your system's appropriate voltage value.

Sourcing Output

In an output slice, the terminology describes what the slice does with the current from the load. In a "sourcing" slice, it "sources" current to the voltage rail. You will need to supply the ground for the load.

MEI has digital inputs for 5, 12-24, or 48 volts. You will need to choose a slice for your system's appropriate voltage value.