Logic with Contacts

AND LOGIC — Series Contacts

Figure 1 - Series Contacts

The figure above executes a logical AND between the last two elements loaded into the STACK, lowers the STACK one level, and pushes the result to the top of the STACK. This means the following Boolean operation is performed: top of STACK = BIT1.BIT2.

In IL (Instruction List) language:

LD    BIT1    (* carrega o valor de BIT1 para o STACK = | BIT1 | *)
LD    BIT2    (* carrega o valor de BIT2 para o STACK = | BIT2 | BIT1 | *)
AND           (* executa AND entre BIT1 e BIT2 -> STACK = | BIT1.BIT2 | *)

Truth Table (AND)

BIT1	BIT2	STACK
0	0	0
0	1	0
1	0	0
1	1	1

OR LOGIC — Parallel Contacts

Figure 2 - Parallel Contacts

The figure above executes an OR logic between the last two elements loaded into the STACK, reduces the STACK one level, and places the result at the top of the STACK. In other words: top of STACK = BIT1 OR BIT2.

In IL (Instruction List) language:

LD    BIT1    (* carrega o valor de BIT1 para o STACK = | BIT1 | *)
LD    BIT2    (* carrega o valor de BIT2 para o STACK = | BIT2 | BIT1 | *)
OR            (* executa OR entre BIT1 e BIT2 -> STACK = | BIT1+BIT2 | *)

Truth Table (OR)

BIT1	BIT2	STACK
0	0	0
0	1	1
1	0	1
1	1	1