This logic group checks a PIN entry with a predefined PIN and reports correct or incorrect.

The 4-digit PIN is transferred to the logic group via the 10 inputs "digit 0" to "digit 9". Here, the value 0 to 9 is only accepted if TRUE. This means that the data point type for the inputs "Digit 0" to "Digit 9" is of the Boolean type (1 bit). The actual value of the digit is generated by the translator tool.
The following translator tools convert the TRUE into the corresponding integer value (0 to 9).
Since the four numbers of the PIN are taken over one after the other, there are four gate elements that are activated one after the other.
This is necessary so that each digit can be multiplied by the correct factor. The factor depends on
the position.

Afterwards, all values are added together with the maths element "Build PIN ..." to combine the four digits entered one after the other to the four-digit value.

The final comparison of the entered and preset PIN is made in the "PIN correct ???" element.
If the entered PIN is correct, the output "PIN Correct" is set to TRUE for 2 seconds. If, on the other hand, the PIN is entered incorrectly, the output "PIN Incorrect" is set to TRUE for 2 seconds.

by Jörg Eschke
(167)