Application Notes

Basics of I/O for Integrated Motor products

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This Application Note covers the connection of the I/O points for Liberty* MDrive and MDrive Plus, MDrive Linear Actuator and MForce products. The I/O differs in connection and application between the two product families in that the MDrive Plus I/O is non-isolated and programmable as an input or an output. The Liberty* MDrive I/O is fixed function is input or output.


  • Liberty* MDrive
  • MDrive Linear Actuator
  • MDrive Plus
  • MForce


  1. DC power supply
  2. Optional: +12 to +24 VDC Auxiliary supply
  3. +5 to +24 VDC power supply for input power. (Required if using inputs.)
  4. Input and/or output devices
  5. Cabling: 22 AWG shielded twisted pairs for I/O, Shielded twisted pair for power, AWG determined by length and current.

*Previously Lexium


Liberty* MDrive

Introduction: Sinking or Sourcing

The terms sinking and sourcing are used in the Liberty MDrive I/O description to describe the configuration of the I/O point with regards to the current flow through the device when active.

  • Sinking: Voltage “sinks” the current to ground.
  • Sourcing: Voltage “sources” the current from a voltage “source.”

Sinking Inputs

Sinking Output

Liberty* Connection Examples

Sinking input

The sink/source operation of the inputs is determined by the reference potential seen at the input reference input. For sinking input operation, the input reference should be connected to the +VDC side of a +5 to +24 VDC supply.

Sinking input – Switch

Open-Collector (NPN) Sinking Interface

Sourcing input

For sourcing input operation, the input reference should be connected to the return (GND) side of a +5 to +24 VDC supply.

Sourcing Input – Switch

Open-Collector (PNP) Sourcing Interface

Analog input

The Analog input may be interfaced to devices outputting the following signal types and used to control applications such as Speed control, torque control, program interactions.:

  • 0 to +5 VDC
  • 0 to +20 VDC
  • 0 to 30 mA
  • 4 to 20 mA

Dry-contact type power outputs

The outputs of the Liberty* MDrive are isolated, dry contact outputs with a voltage range of -24 to +24 VDC and current rating of -100 to +100 mA.


Signal (trip) output

The trip output is a high speed, low current output which can be connected as either open-collector or open-emitter. As this output current range max is 5.5 mA, it should not be used with inductive loads, but only as a signal indicator.

MDrive / MForce

Sinking I/O
A sinking device provides a path for the current to ground. Terms used to describe sinking devices include NPN, Open Collector, Normally High, and IEC Negative Logic.

The Motion Control device’s I/O points are programmable as sinking or sourcing, general purpose or dedicated functions with the active state programmable as HIGH or LOW.

Sourcing I/O

A sourcing device provides the power or a positive potential to an I/O point. Sourcing devices ‘push’ the current through the load. Other terms used to describe sourcing devices include PNP, Open Emitter, Normally Low, and IEC Positive Logic.

Note that sourcing outputs are only available on Motion Control devices equipped with Plus2 expanded features.


*Previously Lexium

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