Checking the transducer by means of the Diagnostics functionality
The purpose of the BITE (Built-In Test Equipment) dialog box is to allow on-line testing and verification of the hardware components in the SU90 system. Use the Transducer page to do a reception test to check the individual transducer elements. Any errors are then easily detected.
Prerequisites
Neither tools nor instruments are required.
For the best possible conditions, the ship must be "silent".
•  The water must be as deep as possible. Recommended minimum depth is 100 metres.
•  There must be no other vessels in the vicinity.
•  The vessel must lie still in the water.
•  As much machinery as possible must be turned off. It is particularly important to turn off electrical motors, as well as cooling systems and hydraulic pumps that may cause electric noise.
•  To prevent interference, all other hydroacoustic instruments must be turned off.
Context
By means of the BITE functionality, you can easily determine if the hardware components in the SU90 system are operational. And most important, you can make sure that all the transceivers channels and transducer elements are functional. Each button provides a small colour coded indicator.
•  No indicatorStatus is OK. No actions are necessary.
•  YellowThis is a warning. A closer investigation is recommended.
•  RedThis is an alarm. A closer investigation is required.
•  BlueA device monitored by the diagnostic system is disabled.
•  GreyNo information is available.
Note
The BITE dialog box and functionality is only provided for performance monitoring. The functionality offered by the dialog box is not required for normal use of the SU90 system. The dialog box does not permit you to change any operational settings.
Procedure
1 Make sure that you have sufficient water depth below the keel before you lower the transducer.
2 Lower the transducer to its bottom position.
3 Select the default settings.
a On the Main menu, select User Settings.
b Observe the Factory Settings list.
c Select the setting you want to use.
d Select Activate Selected Setting.
e Select OK to apply your changes and close the User Settings dialog box.
4 Make the following preparations.
a On the Main menu: Set Range to 1500 m.
b On the Operation menu: Set Tx Power to Maximum (or any other power rating) to start pinging.
c On the Setup menu: Open the BITE (Built-In Test Equipment) dialog box.
5 Select Transducer to open the page.
The Transducer page presents all the elements that are used in the transducer. The presentation attempts to organize the elements in the same manner as in the physical transducer. The transceiver boards are shown as "buttons". Select a transceiver board to highlight the elements that are physically connected to the board.
6 Select Reception Test to start an automatic test of the individual transducer elements.
The reception test validates each single element in the transducer, and returns the status using a simple colour code.
•  GreenThe transducer element is fully operational.
•  RedThe transducer element offers reduced performance.
•  BlackThe transducer element is not working ("dead").
For more information, observe the tooltip provided for each element rectangle.
7 Make sure that the number of unserviceable ("dead") elements does not degrade the performance of the SU90 system.
A small number of unserviceable transducer elements are accepted, even for operational use. This is regarded as "graceful degradation”.
The SU90 system operates with 384 individual channels handled by 12 transceiver boards. If a single channel fails during normal operation, you are not likely to detect it. Even if several channels fail, you may not see it.
The detection of a faulty channel depends on the physical location of the relevant transducer element. If faulty channels are grouped together on the transducer face, this may cause a visible defect in the display presentation. If they are scattered, the visible defect may be a lot harder to see. In all cases, the echoes from the neighbouring channels cause an interpolation that will restore a lot of the degraded presentation.
Which actions to take if single channels fail depend on the operational impact, the overall performance of the SU90 system, and a cost/benefit assessment. The most important factor in the cost/benefit assessment is whether you need to replace the transducer, or just a single transceiver board. If more than 3% of your transducer elements have failed, we recommend that you contact your dealer for advice.
Note
For further investigations of this issue, use the functionality offered by the Element BITE (Element Built In Test Equipment) dialog box.
8 If the result from the reception test shows a number of transducer elements that are either defective or offer reduced performance, repeat the test.
With the vessel in port, the environmental conditions are not satisfactory. In the shallow waters of the port, noise from other vessels, dockyard workers or machinery will cause unreliable test results. If you do this tests in a busy harbour, or with noise sources present, the sensitive receivers will detect all the noise in the nearby waters. Excessive noise or interference may be misinterpreted as physical defects.
You may need to repeat the test several times, and - if necessary - implement a "silent ship" to improve the conditions.
9 Finish the test.
a Close the BITE (Built In Test Equipment) dialog box.
b Set Tx Power to Off.
c Hoist the transducer back up to its upper position.
Further requirements
If the noise level is higher than specified, you must check the reason(s) for this.
•  Check the grounding of the Transceiver Unit.
•  Verify that other electric equipment and/or machinery on board, such as cooling systems, hydraulic pumps, electric motors etc, do not influence on the noise reading. Switch off as much machinery as possible, especially electrical motors.
•  Check for interference from other hydroacoustic systems.
•  Check for environmental noise, such as other vessels in the vicinity or animal life.