Read each line info block

Decoding of the each line info block

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

Decoding

The decoding of the continuous line count is:

C_lc = P_x0Green × 256 + P_x0Blue

Example

C_lc = 217 × 256 + 127 = 55679

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

Decoding

The decoding of the line count is

L_c = P_x1Green × 256 + P_x1Blue

Example

L_c = 0 × 256 + 0 = 0

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

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

Decoding

The decoding of the line time is:

L_t = (P_x2Red × 2¹⁶ + P_x2Green × 2⁸ + P_x2Blue) / 100

Example

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

Encoder clocks

Structure

Decoding

The decoding of the encoder clocks is:

E_c = P_x3Red × 2¹⁶ + P_x3Green × 2⁸ + P_x3Blue

Next line trigger position

Structure

Decoding

The decoding of the encoder clocks is:

N_lp = (P_x4Red × 2¹⁶ + P_x4Green × 2⁸ + P_x4Blue) / 256

Time stamp

Structure

Decoding

The decoding of the time stamp is:

T_s = (P_x5Red × 2¹⁶ + P_x5Green × 2⁸ + P_x5Blue) / 4