The FXMP25 is an external field controller that may be connected digitally to a Mentor MP DC drive using a standard RJ45 connection, allowing set-up by standard drive parameters. The FXMP25 can also function in standalone mode using its integrated keypad and display.



Continuous AC input: 26A

Continuous DC output current: 25A

Inputs and Outputs

Digital input1Field economy level+24V
Analog input1Current demand input0 to 10V
Analog output2Field current output signal

Armature voltage output signal

0 to 10V
Relay3Fail relayNormally open and normally closed

 Overall dimensions


Height: 247mm (9.72in)
Width: 192.38mm (7.57in

Depth: 90.27mm (3.55in)


Every Mentor MP has a motor field controller as standard that provides excellent field control for the majority of DC motors. However, for the following situations, the optional FXMP25 external field controller is recommended:

  • The required field current is greater than that offered by the standard drive, up to 25A. For example, older motors with low field voltages.
  • The field is required to be forced down more quickly than is possible with a standard half controlled field bridge. For example, on spindle motors or motors with high field time constants where the field is required to weaken more quickly than the natural time constant of the field winding.
  • FXMP25 allows applications to be implemented with simple field current reversal, without armature reversal. For example, applications where a rapid change in torque direction is not required. With the Mentor MP it is possible to implement a four quadrant system with a two quadrant armature converter where a slow change in torque direction can be tolerated.

Easy upgrade

The new FXMP25 replaces our existing FXM5 option. It may also be controlled digitally by a Mentor II, allowing set-up by standard drive parameters. The FXMP25 has the same physical dimensions as the existing FXM5, but extends its current range to 25A.

For field currents above 25A, a separate Mentor MP DC drive can be used as a field controller.