PLC piecewise linear table instruction and SSD example

So far we have learned about,

• Piecewise linear table
• shift register
• UART 
• Counter 
• And one shot 

Now we combine, these instruction to make a simple example. In this example the user send the ASCII characters over the UART terminal to the PLC.

Ladder diagram example

A circular counter activates the four digits multiplexed displays. The display port is PORTC. Each digit becomes active for 2 mS.

A set of UART instructions send and receive the characters between the host PC and the PLC. 

A five stages shift register, receives the character sent from UART before it sends to the multiplexed display.

Schematic Diagram

The picture below is a sample of program simulation.

A sample of program

Click here to download the ladder diagram example.