Verifying system operation by means of the Element BITE functionality
The purpose of the Element BITE (Element Built-In Test Equipment) dialog box is to allow on-line test and verification of the individual elements in the transducer. It allows you to see if the transducer elements are operational during transmission and reception. The B-Scan page allows you to monitor the data received from each of the elements in the transducer. The start sample and the number of samples to be displayed are selectable.
Prerequisites
The SU90 system hardware units are installed as specified in this manual.
•  The SU90 system is turned on and operates normally.
•  The SU90 system is in Normal mode, but TX Power is set to Off to prevent transmissions.
•  The transducer is retracted to its upper position.
•  The vessel is berthed or at sea.
Caution
You must never set the SU90 system to "ping" unless the transducer is submerged in water. The transducer may be damaged if it transmits in open air.
Neither tools nor instruments are required.
Context
By means of the Element BITE (Element Built-In Test Equipment) functionality, you can easily determine if the SU90 hardware is operational. The following pages are provided:
Matrix
The Matrix page allows you to monitor the average signal values or signal phases from each of the channels and transducer elements in the SU90 system. The presentation is provided on a matrix corresponding to the element locations in the transducer.
B-Scan
The B-Scan page allows you to monitor the data received from each of the elements in the transducer. The start sample and the number of samples to be displayed are selectable.
In the B-Scan presentation, each element in the transducer is shown as a long coloured vertical rectangle. If you place the cursor on top of one of these rectangles, a small yellow tool-tip will identify key information about the channel.
•  The identification of the transducer element
•  The identification of the transceiver board
•  The current sample you are looking at
•  The measured echo value (in dB)
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 Off.
c On the Active menu:
1 Set Pulse Type to CW Medium.
2 Set Frequency to the start frequency:20 kHz
3 Set Vertical TX Sector to Narrow.
4 Set Noise Filter to Off.
5 Set the Bottom Filter Threshold to Off.
d On the Setup menu: Select Diagnostics to open the dialog box.
5 Select Processor to open the page.
6 Open the Element BITE (Element Built-In Test Equipment) dialog box.
a Select Element BITE to open the dialog box.
b Select the B-Scan tab to open the page.
c Select Element amplitude.
7 Test the receiver performance.
a Set Start sample to 5000.
b Set Sample range to 10000.
c Look at the pattern in the B-Scan presentation, and compare them with the example provided.
Image

This screen capture shows the B-Scan pattern while testing the receiver in the near range. This is a generic illustration. Any similarities with specific products are accidental.
To detect unserviceable transducer elements and/or transceiver boards, you must compare the rectangles. When operating the SU90 system in port, the colours will be less homogeneous due to the environmental noise and the shallow depth. During normal operation at sea the colours will be homogeneous.
•  If a single element is "dead" (no transmit, no receive), the rectangle is easily spotted because its colour is black.
•  If a single element is receiving, but not transmitting, the rectangle is normally presented in lighter shades of blue.
•  If a transceiver board is "dead" (no transmit, no receive), all the transducer elements connected to the board are easily spotted because they are all black.
8 Test the transmitter performance.
a Set Tx Power to Maximum.
b Set Start sample to 50
c Set Sample range to 2000
d Look at the pattern in the B-Scan presentation, and compare them with the example provided.
Image

This screen capture shows the B-Scan pattern while testing the transmitter. You can clearly see the transmit pulse.
9 Make sure that there are no weak elements in the transmission sample range.
If any weak elements are detected, record these in the result table.
10 Make sure there are no black lines in the transmission and reception sample range.
A black line indicates an unserviceable transducer element. If any such elements are detected, record these in the result table.
11 Finish the test.
a Close the Element BITE (Element Built-In Test Equipment) dialog box.
b Close the Diagnostics dialog box.
c Set Tx Power to Off.
d Set Operation to Inactive.
e Hoist the transducer back up to its upper position.
Result
Requirements Results
The information presented by the B-Scan page verifies that the SU90 system is fully operational.  
All elements are operational in both transmit and receive. The maximum number of bad elements is:  4  
Weak elements:
Unserviceable elements:
Date and signature: