Danfoss PVED-CLS User Manual

© Danfoss | August 2018 AQ00000211 | 39
ENGINEERING TOMORROW
This check ensures that the cut-off valve can achieve the blocked state, when the cut-off solenoid valve is de-energized.
By moving the EH-valve main spool in the mechanical deadband, it is ensured that no oil flow is send to the steering
Important
Electro-hydraulic steering (Auto-guidance, Fast-steering and AUX-steering) will not be enabled before the PVED-CLS
has passed this test.
Warning
By setting P3078
: Cut-off valve monitoring POST timeout to 0 (Bypass off-road safety check), the Cut-off valve
diagnostics are disabled.
Important
• In most cases this test will be completed within 1 second, but if the oil has a very high viscosity, the time for
completing this test will increase; hence Danfoss recommends a relatively high value for P3078 to ensure the
PVED-CLS does not goes into fail safe mode in cold conditions.
• If PVED-CLS is commanded to go to off-road mode before pump pressure is available, PVED-CLS will not be
able to perform this self-test and hence fail after the specified timeout set by P3078.
Name
Address
Data type
Unit
Description of parameter
User
Range
Danfoss default value
Safety critical parameters ‘S’
Min.
Max.
Cut-off valve
monitoring POST
timeout
P3078 U16 x10mSec
Cut Off Valve Activation Timeout for COV Monitoring feature while
entering Off Road state.
INFO: Setting this parameter to 0 will bypass off-road safety check
OEM 0 1000 900 S
Table 9
7.1.2.2 Cut-off valve monitoring for EHi-H
This safety check will be executed if P3081: Valve type is set to 2 (EHi-H) and a mode change from on-road mode to
off-road mode is requested. The cut off valve monitoring for EHi-H consists of IMD safety checks.
The PVED-CLS will set the EH-valve main spool set-point to a positive value inside the hydraulic deadband and
alternately turn the cut-off solenoid valve on and off. Each time the COV solenoid valve is toggled, the time is measured
from it is toggled until the EH-valve main spool has been observed moving. The measured time is then evaluated against
the value of P3098: Safety-checks IMD – Rise time limits and P3099: Safety-checks IMD – Fall time limit, for the rise
time (cut-off solenoid valve turned on) and the fall time (cut-off solenoid valve turned off) respectively. Once the
consecutive number of test passed, both rise times and fall times, is equal to the value of P3100: Safety-checks IMD –
Pass criteria, the test is evaluated as passed and it will be repeated with a negative EH-valve main spool set-point. Once
this test has passed as well, the PVED-CLS will be allowed to go into off-road mode.

Danfoss PVED-CLS Specifications

General

Brand	Danfoss
Model	PVED-CLS
Category	Controller
Language	English