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Testing
1. Touch the Mask Violation Locator tab to display the mask testing dialog
2. Touch the On checkbox to begin testing the signal bits against the selected mask.
3. ASDA-J option only: Failed bits are displayed in a table and as a waveform in the lower grid.
The scale of the lower grid in which the failed bit waveform is set by the Bits in Locator field.
The failed bit is centered around the middle two divisions and the vertical scale is the same
as the eye pattern.
4. Touch the Stop On Error checkbox if you want to halt testing when an error occurs. But
testing will continue until the end of the acquired waveform is reached.
5. ASDA-J option only: Touch the Show Location checkbox, then touch inside the Show field
and select All or Near X-Y from the pop-up menu. All means that all failures will be shown,
regardless of where they occur in the eye pattern. Near X-Y means that if you select a failure
marker, either by touching the marker on the waveform or by touching the bit number in the
Failures list, only the subsequent failures near the selected marker will be shown.
Note: The X and Y coordinates indicate the position of the selected failure on a grid normalized to one, read from left to
right and top to bottom.
6. ASDA-J option only: Touch inside the N Failures field and, using the pop-up keypad, enter
the number of failures after which data accumulation will end, up to 10,000. Multiple failures
can occur on each bit, so the value of N failures will always be equal to or greater than the
number of failed bits.
7. ASDA-J option only: Touch inside the Bits in Locater field and, using the pop-up keypad,
enter the number of bits to be displayed in the bad bits trace. This trace shows the part of the
waveform that violates the mask.
Bit Error Rate - ASDA-J Option Only
1. Press the SDA front panel button; or, touch Analysis in the menu bar, then Serial Data in the
drop-down menu. The display defaults to the "Scope" dialog, which enables you to set up
SDA measurements while you continue to view currently displayed waveforms.
2. Touch the BER button. This brings you to the BER setup dialog.
3. Under "Pattern," touch inside the Method field and select Pattern (expected bit pattern in the
data stream), PRBS (a pseudo-random bit sequence), or File (a saved user ASCII hex file).
4. If you chose Pattern, use the pop-up keyboard to enter a hexadecimal number as a bit
pattern. If you chose PRBS, touch inside the PRBS Sequence field and select a bit
sequence from the pop-up menu. The digit at the end of PRBSx represents the number of
shift registers to be used in the generation of the pseudo-random bit sequence used for BER
testing. The sequences generated for each n value are as described in ITU-O.150. If you
chose File, enter the path to the file, using the pop-up keyboard; or, touch the Browse button
and navigate to the file.
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SDA-OM-E Rev H
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