KONGSBERG MRU-E-JB1 Host machine
KONGSBERG MRU-E-JB1 Host machine
MRU product line continuation
End-of-life for older MRU
models
The blue Motion Reference Unit (MRU) models, serial numbers 19000 and
below, are now all obsolete and replaced by the following 5th generation
MRU models:
• MRU 5v
• MRU Hv
• MRU 3v (replacing MRU Z)
• MRU 2v
• MRUDv
• MRU E
As published in the End-of-life note of October 2012. support for these
older versions will be limited after November 2023.
As we have past this date, we kindly ask you to consider upgrading the
affected MRU version, as repair and recalibration of these units will now
be limited.
Junction Box
JB3 Junction Box
5th generation MRU and mounting bracket
The now discontinued 4th generation MRU was supplied
with the JB1 Junction Box. The new 5th generation MRU is
supplied with the JB3 Junction Box.
A new 5th generation MRU can be connected directly
to the older JB1. hence replacing the JB1 is not
needed. However, be aware that the COM2 and analog
outputs will not be available with the JB1. In addition,
configuration of the 5th generation MRU must be
done through the service kit (MRU-T-Configkit-V).
Brackets
The new 5th generation MRU is compatible with all
exisiting MRU mounting brackets from the 4th generation
MRUs.
Subsea bottles
The 5th generation MRU is physically shorter than the 4th
generation MRU. This means that you will not be able to
fit a new MRU into an old subsea bottle, hence these will
also have to be replaced.
Cables
Both generations of MRUs have the same physical
connector, hence cables do not directly need to be
replaced. Note: As functionality/interface has changed
between the two generations, please ensure that
connections are referred to the 5th generation MRU.
Note:
• Analog signals are not available directly from the 5th
generation MRU.
• Old subsea cables (MRU-E-CS4) are not compatible
with the new 5th generation MRU when Ethernet
communication is used.
Interfaces
Many output variable names have changed – please
consult the Installation Manual for the 5th generation
MRUs
Connector x
Input serial lines (AUX1. AUX2) (COM3. COM4) x
Cables for serial comm x
MRU Junction Box
MRU-E-JB1 x (serial comm.
only)
MRU-E-JB1P x (serial comm.
only)
MRU-E-JB2 x (serial comm.
only)
MRU-M-JB3 x
MRU Cables
MRU-E-CS1 (3. 5. 10. 15. 20. 30 m) x (serial comm.
only)
MRU-E-CS5 x
MRU-E-CS8 (3. 10. 30 m) x
MRU-E-CS10 (6. 10 m) x
MRU-E-DP1 (MRU D only) x (serial comm.
only)
MRU-E-DP2 (MRU D only) x
MRU-E-HYD (10. 20 m) x
MRU mounting brackets
MRU-M-MB1 x
MRU-M-MB3 x
MRU-M-MB4 x
MRU-M-MB5 x
MRU-M-MB6 x
MRU cables subsea
MRU-E-CS4 x
MRU-E-CS7 (15. 30. 45 m) x
MRU-E-CS9 (15. 30. 45 m) x
MRU subsea bottles
MRU-M-SB5 x
MRU-M-SB6 x
MRU-M-SB7 x
MRU-M-SB9 x
MRU-M-SB10 x
MRU-M-SB11 x
MRU-M-SB12 x
MRU-M-SB14 x
MRU-M-EX1
Signals available from MRU 4th gen. 5th gen. Not changed
/both
Ethernet x
RS-232 x
RS-422 (only via JB1) x
MRC (WinMRC and DOSMRC), serial line x
MRC+, Ethernet x
PFreeHeave x
Analog channels x (only via JB3)
Internal time delays over MRU generations
Sensor interface delay (ta
) 5 ms 2.5 ms
Main processing time (tb
) 2.5 ms <1 ms
Digital line request response time (polled out) (tc
) 10 ms ± 10 ms 2.5 ms ± 2.5 ms
Output data preparation (td
) 0.8 + n • 0.2 ms 0 ms
Digital line request response time (polled output) (te
) 2.5 ms ± 2.5 ms 0 ms
Transmission delay on serial line (tf
) (n + l) •
40000/b ms
Polling message transmission delay (tg
) 50000/b ms
Time delay by cyclic digital output at MRU connector
(4 variables) (t = ta
+ tb
+ td
)
9.1 ms <3.5 ms
Group delay on angular rate (variable 1. 2 and 3) 25 ms 30 m