Basler L301kc Line Array Camera Technology and Troubleshooting

Important constraint: Spatial correction is only available in 8-bit output mode and automatically disabled in 10 bit mode. Test image modes 1 and 2 will also force the delay to be set to 0 (disable spatial correction).

Output mode selection and data timing

L301kc provides five output modes to adapt to different frame acquisition card bandwidths and processing capabilities:

Mode Pixel Clock Data Bit Depth per Cycle Application Scenarios

20MHz 8-bit RGB 20MHz RGB three pixel simultaneous 8-bit standard color acquisition, good compatibility

60MHz single pixel 8-bit 60MHz single channel/cycle 8-bit high-speed transmission, requiring a high bandwidth acquisition card

60MHz single pixel 10 bit 60MHz single channel/cycle 10 bit high dynamic range, requires a 10 bit acquisition card

40MHz Dual Pixel 10 Bit 40MHz Dual Channel/Period 10 Bit 10 Bit Bandwidth Compromise Solution

High speed compromise solution for 40MHz dual pixel 8-bit 40MHz dual channel/cycle 8-bit 8-bit

The data output sequence is fixed as red → green → blue, and the Line Valid (LVAL) signal remains high during effective data transmission. The frame acquisition card needs to correctly parse the row data based on the LVAL signal.

Detailed explanation of exposure control mode

5.1 ExSync external synchronization mode

Triggered by external ExSync signal control line:

Edge control: The exposure time is equal to the ExSync cycle (rising edge to rising edge), and the charge accumulates throughout the entire cycle.

Level control: The exposure time is determined by the ExSync low-level time, and charges only accumulate during the low-level period.

Programmable control: The rising edge triggers the start of exposure and lasts for a preset time (Timer 1 setting), commonly used in scenes that require precise exposure time.

5.2 Free run mode

No external synchronization required, continuous trigger signals are generated by internal Timer 1 and Timer 2:

Edge control: The exposure time is equal to the internal period.

Programmable control: Timer 1 sets the low-level time (i.e. exposure time), Timer 2 sets the high-level time.

Key limitation: Maximum line frequency of 8.0kHz (space correction enabled) or 9.20kHz (disabled), exceeding the limit will trigger a "line frequency exceeding" error, and some lines will output all zero values.

Image quality tuning: gain, bias, and digital shift

6.1 Gain and bias settings

Gain: adjustable range of 96-1023 (decimal), corresponding to 0dB to 33.6dB. As the gain increases, both the signal and noise are amplified simultaneously, while the SNR remains basically unchanged. It is recommended to prioritize adjusting brightness through lighting and exposure time rather than relying on gain.

Offset: Adjustment range 0-255 (decimal). In 10 bit mode, every 4 units of bias increase the output by 1 DN value; Add 1 DN value for every 16 units in 8-bit mode.

White balance adjustment suggestion: First fix the gain of the channel with the strongest response, and then adjust the other two channels to make the RGB values of the white object equal.

6.2 Digital Shift

By changing the output bit mapping to achieve signal multiplication, it is suitable for improving brightness under low light conditions:

No displacement: Normal output ADC original 10 bits or high 8 bits

Displacement once (2X): Discard the most significant bit and output the second highest bit to LSB

Displacement twice (4X): Discard the higher two digits

Displacement three times (8X): Discard the high three digits

Pre use verification: In 8-bit mode, if the maximum pixel value exceeds 128, 2X displacement cannot be used; If it exceeds 64, 4X cannot be used; if it exceeds 32, 8X cannot be used, otherwise it will cause saturation limiting (high position 1 and low position 1).

Area of Interest (AOI) and Test Images

7.1 AOI Function

You can specify the starting pixel (1-2098) and length (1-2098), and only output pixel data within the specified range. Attention: AOI will not increase the maximum line frequency, but it can reduce the amount of data transmitted per line and lower the processing pressure on the acquisition card.

7.2 Test Images

Built in 6 types of test images:

Grayscale gradient (full channel)

Vertical movement grayscale gradient

Horizontal grayscale gradient (used to verify whether spatial correction is effective)

red gradient

green gradient

blue gradient

Test image 3 can be used for intuitive verification of spatial correction delay settings: when delay=0, the RGB values of the left and right halves of the image are equal; When the delay is 8, the RGB values of the same pixel in the right half differ by 8 DN.

Configuration method: CCT+tool and binary protocol

8.1 Camera Configuration Tool Plus（CCT+）

A graphical Windows tool that communicates with the camera via Camera Link serial port (RS-644). Parameter grouping management (output, exposure, gain/bias, AOI, etc.), with immediate effect upon modification. Support saving work configurations to one of 15 user configuration groups and setting a Startup Pointer to determine which configuration group to load when powered on.

8.2 Binary Command Protocol

Suitable for automation integration, sending frame format commands through Camera Link standard API (clser *. dll) or Basler CPA driver: