PLC-controlled LED chessboard

Description
This SCL function block FB_LED_MatrixControl multiplexes an 8×8 LED matrix: Every 5 ms, a column is activated and the corresponding row pattern is output. The variable PatternID allows you to select predefined patterns such as a checkerboard, vertical chaser, or a reproducible pseudo-random pattern.

Note: All modules are designed exclusively as a learning and optimization basis and are not approved for live operation. System modules, in particular, must be finally tested and commissioned by qualified personnel before productive use.

How it works

1. TimerColumn (PT=T#5 ms) ticks → Column index = (Column index+1) MOD 8
2. Output column bitmask according to column index
3. Apply row pattern[column index] to row exits
4. Pattern ID change or reset → CASE structure loads new row pattern array, update status text
5. Reset → Delete pattern, status text “Reset”

Technical details
• Inputs/Variables: TimerColumn, ColumnIndex, PatternID, LastPatternID, Reset
• Outputs/Variables: Columns (bit mask), Rows (byte), Row pattern[0..7] (array), StatusText
• Modulo-8 calculation for column index and bit masks
• Pattern preparation using FOR loop and CASE for three predefined patterns
• Fallback if pattern ID is invalid deletes the array

Possible applications
• Pixel graphics and running lights on 8×8 modules
• Pseudo-random effects in prototypes and demos
• Training and trade fair installations with LED matrix

compatibility
Siemens S7-1200 & S7-1500 PLC, TIA Portal V13 or higher (V16+ recommended for PLCSIM & HMI)

Scope of delivery
.scl file with input/output declaration, timer instance, CASE logic, and header comments; download link available immediately after purchase

Support
Adaptation of own pattern algorithms, extension to larger matrices, HMI integration or additional animations on request via shop message or email.