Dalsa Piranha 2 Series, Руководство пользователя

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18 Piranha 2 User’s Manual
03-032-00493-14 Teledyne DALSA
Test Pattern Pixels and End-of-line Sequence
To facilitate system -level d ebu gging and verification of d ata p ath integrity, the cam era
can generate a test p attern. The test p attern is a ram p from 0 to 255DN , then starts at 0
again. Use the test p attern to verify the p rop er tim ing and connection s betw een the
cam era and the fram e grabber.
To alleviate p ost-p rocessing, Piranh a 2 offers an end -of-line sequ ence that p rovid es basic
calcu lations inclu d ing "line cou nter", "line average", "p ixels above thresh old ", "p ixels
below threshold ", and "d erivative line su m ". These basic calcu lation s are the center of
m ost au tom atic gain control (AGC) algorithm s.
To fu rther aid in d ebu gging and cable/ d ata p ath integrity, the first six bits of the ou tp u t
of the end -of-line sequ ence are "aa", "55", "aa". Refer to the table below .
Location Value Description
1
A’s
By ensu ring these valu es consistently toggle
betw een "aa" and "55", you can verify cabling
(i.e. no stu ck bits)
2
5’s
3
A’s
4 4 bit cou nter LSB ju stified Cou nter increm ents by 1. Use this valu e to
verify that every line is ou tp u t
5 Line su m LSB Use these valu es to help calcu late line
average
6 Line su m MID
7 Line su m MSB
8 0
9 Pixels above threshold LSB Monitor these valu es (either above or below
threshold ) and ad ju st cam era gain to keep
these valu es relatively constant. This
p rovid es a basis for au tom atic gain control
(AGC)
10 Pixels above threshold
MSB
11 Pixels below threshold LSB
12 Pixels below threshold
MSB
13 Derivative line su m LSB Use these valu es to focu s the cam era.
Generally, the greater the su m the greater the
im age contrast
14 Derivative line su m Mid
15 Derivative line su m MSB
16 0
For information
on the test pattern
and end of line
sequence
commands, see
section 3.17
Generating Test
Patterns.
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