NAVIS NavDP 4000 Series Operation Manual page 115

Thrusters
The above described is normal operation.
While the thruster is under DP control, NAVIS NavDP 4000 maintains SELECT signal, and the thruster system
maintains READY signal in response. If NAVIS NavDP 4000 releases SELECT signal then the thruster system releases
READY signal in response. See Figure 6.24.
The thruster system can release READY signal without SELECT signal released, which means that the thruster is out
of the DP control.
When the thruster system releases RUN signal it means that the thruster is not available for DP operation. In this case,
SELECT and READY signals are to be released.
Without RUN signal, NAVIS NavDP 4000 does not know whether the thruster is available for DP. It is very similar
to the requirement of monitoring if data from sensors and position reference systems is available for DP, regardless of
whether NAVIS NavDP 4000 active or not.
6.2.4.3 Failure Mode — RUN Signal Lost
If a thruster does not send RUN signal then, independently of the position of the Mode Selector, the thruster's state is
indicated as
This situation is faulty, which is signalized by the Flt indicator colored red. In this situation the thruster is not available
for DP, and the thruster control softkey is grey in whatever position the Mode Selector is set.
Since the thruster can later be available for DP, you must properly put it into operation. There are two common
situations.
a) The Mode Selector is set to MANUAL position. After RUN signal has recovered, the thruster's state is indicated
as
and the thruster control softkey remains grey. The next steps are described in section "Normal Operation"
b) The Mode Selector is set to IJ or DP position ( NAVIS NavDP 4000 is active). After RUN signal has recovered,
the thruster's state is indicated as
and the thruster control softkey gets red, which means that the thruster has just recovered from a failure mode. Press
the thruster softkey. It starts blinking. Press the softkey once again to cancel, or press ENTER softkey to acknowledge.
The operation is available for a thruster group. Press and hold any of the red-colored thruster softkeys until the dialog
box shown in Figure 6.25 appears.
After pressing ENTER, (or Yes) NAVIS NavDP 4000 immediately sends SELECT signal to the thruster, (or thruster
group) and starts waiting for READY signal in response. This situation is shown below
Doc. 000.JDP-10000-OME, rev.3.3.13/"2102.$–17A-Advanced"
Figure 6.24: Signals exchange
Run Select Ready Fault
Red White White Red
Run Select Ready Fault
Green White White
Run Select Ready Fault
Green White White
Figure 6.25: Dialog box
Red
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