Read each line info block
    • 23 Sep 2024
    • 4 Minutes to read
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    Read each line info block

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    Article summary

    Decoding of the each line info block - RGB

    Pixel

    0

    1

    2

    3

    4

    5

    6

    7

    8

    9

    Red

    Marker

    Error code

    Speed2high

    Encoder clocks

    Next line position

    Time stamp

    Unsupported

    Unsupported

    Unsupported

    Marker

    Green

    Continuous line count

    Line count

    Line time

    Blue

    Continuous line count

    This counter increments by 1 for each row of the image. The counter continues counting for new images and is not reset. It can be used to detect missing image information.

    Structure


    Continuous line count

    Byte 1

    Byte 0

    Px0Red

    Px0Green

    Px0Blue

    Decoding

    The decoding of the continuous line count is:

    Clc = Px0Green × 256 + Px0Blue

    Example

    Clc = 217 × 256 + 127 = 55679

    svg-read each line-continuous line count_03

    Example: Decoding of continuous line count 

    Line count

    This counter increments by 1 for each row of the image. The counter starts counting at 0 for each image. It can be used to detect missing image information.

    Structure


    Line count

    Byte 1

    Byte 0

    Px1Red

    Px1Green

    Px1Blue

    Decoding

    The decoding of the line count is

    Lc = Px1Green × 256 + Px1Blue

    Example

    Lc = 0 × 256 + 0 = 0

    svg-read each line-line count_03

    Example: Decoding of line count

    Speed too high

    This information can be used to check if the speed of the line trigger signal is too high for the camera. In this case, the camera switches to freerun and acquires with the maximum possible speed. This state must be avoided because the transport resolution of the image is not constant. If the flag is “True” for some lines there are the following options to avoid this issue.

    The speed too high state can be caused by two parameters

    • Exposure time (Exposure time ≥ Line time - 2us offset)
      Compare the exposure time with the info block information “line time“ to check if the exposure time is the limiting factor.

    • Interface speed

    To avoid the speed too high state there are multiple options.

    • Reduce the transport speed if possible.

    • If the info block information “line time“ oscillates heavily check the electrical connection or try to stabilize the mechanical transportation process.  

    • If the exposure time is the limiting factor reduce the exposure time.

    • If the interface speed is the limiting factor, increase the interface speed is possible (Use more CXP lanes or a faster CXP type / Use dual 10GigE)

    Structure

    Speed2high

    Bit 7

    Bit 6 – Bit 0

    Px2Red

    Line time

    This information represents the line time. For an operation without a line trigger, this variable is constant and equal to the camera parameter line time. If the camera is triggered with a line trigger this information can be used to check the signal/mechanical transport quality.

    • If the signal oscillates very heavily with a high frequency the electrical connection is not OK.

    • Small oscillations (for example +-20%) are most probably mechanical vibrations in the transport process.
      These effects are typical for:

      • Belt drives

      • Conveyor belts

      • Low-quality linear stages for scans with a high resolution.

    Structure


    Line time clocks

    Bit 7 – Bit 4

    Bit 3 – Bit 0

    Byte 1

    Byte 0

    Px2Red

    Px2Green

    Px2Blue

    Decoding

    The decoding of the line time is:

    Lt = (Px2Red × 216 + Px2Green × 28 + Px2Blue) / 100

    Example

    Lt = (0 × 216 + 21 × 28 + 124) / 100 = 55 µs

    svg-read each line-line time_03

    Encoder clocks

    Structure

    Encoder clocks

    Byte 2

    Byte 1

    Byte 0

    Px3Red

    Px3Green

    Px3Blue

    Decoding

    The decoding of the encoder clocks is:

    Ec = Px3Red × 216 + Px3Green × 28 + Px3Blue

    Next line trigger position

    Structure

    Next lt pos raw

    Byte 2

    Byte 1

    Byte 0

    Px4Red

    Px4Green

    Px4Blue

    Decoding

    The decoding of the encoder clocks is:

    Nlp = (Px4Red × 216 + Px4Green × 28 + Px4Blue) / 256

    Time stamp

    Structure

    Time [s]

    Time [¼ ms]

    Byte 2

    Byte 1

    Byte 0

    Px5Red

    Px5Green

    Px5Blue

    Decoding

    The decoding of the time stamp is:

    Ts = (Px5Red × 216 + Px5Green × 28 + Px5Blue) / 4

    Decoding of the each line info block - mono

    Pixel

    0

    1

    2

    3

    4

    5

    6

    7

    8

    9

    Mono

    Continues line count

    Continues line count

    Speed to high / Line time

    Line time

    Encoder Clocks

    Encoder Clocks

    Encoder Clocks

    State of external input line

    Continues line count

    This counter increments by 1 for each row of the image. The counter continues counting for new images and is not reset. It can be used to detect missing image information.

    Structure

    Continuous line count

    Byte 1

    Byte 0

    Px1 (Content of Pixel Position 1)  

    Px2

    Decoding

    The decoding of the continuous line count is:

    Clc = Px1 × 256 + Px2

    Line time

    This information represents the line time. For an operation without a line trigger, this variable is constant and equal to the camera parameter line time. If the camera is triggered with a line trigger this information can be used to check the signal/mechanical transport quality.

    • If the signal oscillates very heavily with a high frequency the electrical connection is not OK.

    • Small oscillations (for example +-20%) are most probably mechanical vibrations in the transport process.
      These effects are typical for:

      • Belt drives

      • Conveyor belts

      • Low-quality linear stages for scans with a high resolution.

    Structure

    Line time

    Byte 1

    Byte 0

    Px3

    Px4

    Decoding

    The decoding of the line time is:

    Lt = (Px3 × 28 + Px4 )× 25 / 100

    Encoder clocks

    24Bit encoder counter. Starts with Power on at 0 and overflows at 2^24. Counts, depending on the operating mode set, either the line trigger pulses or the encoder pulses. Can be used as location information of the document within the batch (sequence).

    Can be reset via EnableIncremets(SelectEncoder(9:7)).

    Structure

    Encoder clocks

    Byte 2

    Byte 1

    Byte 0

    Px5

    Px6

    Px7

    Decoding

    The decoding of the encoder clocks is:

    Ec = Px5 × 216 + Px6 × 28 + Px7

    State of external Inputs

    Structure

    State of external Inputs

    Byte 0

    Px8

    Output List

    Line

    Output Signal in Pixel position 8

    Line1

    8

    Line2

    9

    Line3

    10

    Line4

    11

    Line5

    12

    Line6

    13

    Line7

    14

    Line8

    15

    Decoding

    The decoding of the encoder clocks is:

    Ei = Px8


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