Inductive Transducer, Lvdt (Linear Variable Differential Transformer); Integrated Pulse Width Modulation; Led - Danfoss pved-cl Operation Manual

Operation Manual
PVED-CL Controller for Electro-Hydraulic Steering, Version 1.38
Configuration and Adjustment
© Danfoss | May 2016
Set point
Solenoid
valve bridge
Feedback signal

Inductive Transducer, LVDT (Linear Variable Differential Transformer)

When the main spool is moved, a voltage, proportional to the spool position, is induced. The use of LVDT
gives contact less monitoring of the main spool position. This means an extra long working life and no
limitation as regards the type of hydraulic fluid used. In addition, LVDT gives a precise position signal of
high resolution.

Integrated Pulse Width Modulation

Positioning of the main spool in the PVED-CL is based on the pulse width modulation principle.

LED

A three-color LED on the top of the PVED provides high-dependable information of 4 basic states of the
electronic hardware.
Inactive: No electric power
Green: The PVED controls the spool movement inside the valve.
Yellow: The magnetic valves are temporary disabled due to the power saving feature or until the PVED is
operated. The magnetic valves can also permanently be disabled due to a major fault in the PVED or
wrong signal reception. The CAN bus communication is still operational for diagnostics according to
protocol definition. The spool position control is disabled.
Red: The PVED has detected a critical fault or inconsistency and has executed a "failed silent" procedure.
The spool position controller (Magnetic valves) is disabled. CAN is disabled for diagnostics.
LED
In case the LED indicates yellow, details of the fault can be retrieved from the persistent error buffer and
transmitted on CAN. For more information on this topic see
Spool pos.
Spool or piston
Transducer
Diagnostic & Troubleshooting on page 101.
11025583 | AQ00000216en-US0302 | 21