Service manual

LUMISCAN ACR-2000 SERVICE MANUAL – SECTION 7.0 DIAGNOSTICS
Test Lookup Table Load and Readback Function
From the DDT menu choose 4. Load LUT. A list of choices will be displayed. Select 1 = 0:4095 12
Bit Lut. Select 15. Choose 5: Read LUT. Select 15 . All 4096 values (in hex) will scroll up the
screen in lines of 16. Observe the last column as it scrolls: Verify that the last digit is always "F" while
the first digit of the last column increments from "0" through "F". The last few lines will remain on the
screen. Verify that the last line is:
FF0 FF1 FF2 FF3 FF4 FF5 FF6 FF7 FF8 FF9 FFA FFB FFC FFD FFE FFF
followed by a return to the menu.
Test Digital-only Data Path
From the DDT menu choose 11. Change Parameters and then 6. Lines Per Image and enter 1024.
Return the the main menu and select 13. Diagnostic Scan. From the submenu choose 7- Diagnostic
Pattern. In response to the query "Do overlapped writes to a LSDT.IMG [default=y]", just press Enter.
Wait for the return to the main menu. This causes the DACQ under test to generate a test pattern
consisting of 256 lines of data values 0 through 1023, followed by 256 lines of data values 1024
through 2047, and so on.
From the DDT menu enter the following command line: H12, the following line will appear:
hist12 0 lsdt.img 1024 1024 0 2048 | more
This executes the program HIST12, which counts the number of occurrences of each data value in the
range 0 through 4095, any displays the results on the screen which you can pause by hitting <ctrl>S,
then any key to resume. Examine each screenful and verify that every reported count is 256. Hit any
key (such as the spacebar) to display the next screenful; repeat for the entire file and until the DDT
menu returns.
Verify that the last line displays the following message:
"Total Occurrences = 1048576". (which is 1024 pixel X 1024 lines).
When complete the screen returns to the main menu.
Repeat this entire test, except in the submenu choose 6- Flat Field Pattern. When the results of
HIST12 are displayed, verify that the reported count for every value is 0 except for 1285, which should
have a count of 1048576.
Choose 11: Change Parameters. Select 9- LSB/MSB. This will reverse the order to MSB first. Hit
<enter> to return to main menu. Repeat the diagnostic scan with mode 7- Diagnostic Pattern Repeat
the HIST12 analysis. This time, since the byte ordering has been reversed the results reported by
HIST12 should be as follows: As the numbers scroll past you should see 16 groups of 16 consecutive
bins with 4096 counts each, and all other bins with 0 counts. The groups will be located at bins 0
through 15, 256 through 271, 512 through 527, and ending with 3840 through 3855.