KONGSBERG BWMS system operation and maintenance

Reconfigure alarm mapping in MOS: Under the "Alarm Routing" menu, select "Master Level" and check the actual physical output channel number.

7.3 Fault 3: The system cannot power on or intermittently restarts

Phenomenon: The bridge deck panel is black or randomly restarted during normal operation.

Possible reasons:

The DC power supply voltage is lower than 18V (such as being powered by batteries or experiencing excessive voltage drop in the line).

Power Switching Unit (PSO) malfunction, internal relay shaking.

The electrolytic capacitor on the main control board is aging.

Solution steps:

Measure the voltage at the power supply terminals of the bridge deck panel. If it is between 15V and 17V, check if the 24V charger output on board is normal and increase the cross-sectional area of the wire. If the voltage is higher than 32V, it indicates that the voltage regulator has failed, and the power should be immediately disconnected and replaced.

Temporarily bypass the PSO and connect directly to a stable 24V battery pack. If the system is restored to stability, the PSO is faulty. Refer to document AD-00479 to replace the PSO module.

For old batches of equipment, if the capacitor bulges or leaks, contact Kongsberg after-sales for board level repair.

7.4 Fault 4: MOS-33 cannot connect to DPU or bridge panel

Phenomenon: "Comm Error - No Response from Bridge Panel" is displayed on the operation station.

Possible reasons:

Communication cable open circuit or wiring error (A/B wires reversed).

The terminal resistance is not set correctly (in the case of CAN fieldbus).

DPU address conflict.

Solution steps:

Check if the CAN-H and CAN_L wires are correctly connected to all nodes and if the shielding layer is well grounded. The terminal resistor should be connected in parallel with a 120 Ω resistor at each end node of the bus.

Check the dip switch of each DPU to ensure that the address is unique and consistent with the MOS configuration table.

Measure the differential signal voltage using an oscilloscope. During normal idle, CAN-H is about 2.5V to ground and CAN_L is about 2.5V; during communication, the two change in phase. If there is no signal, the main controller is damaged.

Regular maintenance and recommendations for extending lifespan

8.1 Monthly inspection items

Clean the screens and buttons on the bridge deck to prevent poor contact caused by salt spray crystallization.

Test all alarm transfer paths: manually trigger the "unmanned" simulation to confirm that the captain and backup navigator can receive the actual alarm.

Measure the power supply voltage and record it in the engine log. If it drops more than 0.5V compared to the last time, check the circuit or power module.

8.2 Annual Plan

Remove the panel and check for oxidation or looseness in the internal connectors; Apply anti loosening glue to the fasteners.

Use dry compressed air (≤ 3bar) to blow away dust inside the DPU cabinet.

Backup all current configuration parameters to a USB flash drive or laptop through MOS-33 to prevent the need for recovery during device replacement.

8.3 Suggestions for spare parts

According to equipment failure statistics, the following spare parts should be kept on board:

1 bridge deck main control panel (spare part number can be obtained from the label)

2 RDo-16 output DPUs (as relays are vulnerable components)

1 PSO power switching unit

Several 5 × 20mm slow melting fuses (5 each for 2A and 5A)

Differences from the old version of BNWAS and upgrade precautions

Some ships are still using the previous generation BNWAS (which only has a simple timing reset function and no graded alarm transfer or implicit interactive detection). When upgrading to Kongsberg BWMS, please note:

The original alarm light bell can be reused, but it needs to be connected to the RDo-16 output module.

If the original system does not have a motion sensor, it is necessary to install a PIR probe recommended by Kongsberg and adjust the installation angle.

The NMEA interface with the newly installed radar/ECDIS may require a converter (such as RS422 to CAN), it is recommended to contact the original factory to obtain the adapter box.

After completing the upgrade, it is necessary to conduct IMO compliance testing again: simulate driver incapacitation, measure the actual triggering time from timeout to the second level alarm, and ensure that the deviation from the set value does not exceed ± 5%.