Chapter 9 
129 
Logic programming – Function blocks 
 
Truth table for AND evaluation with eight inputs 
Input 1  Input 2  Input 3 Input 4 Input 5 Input 6 Input 7  Input 8  Output 1
0 x x x x x x x  0 
x 
0 
x x x x x x 
0 
x x 
0 
x x x x x 
0 
x x x 
0 
x x x x 
0 
x x x x 
0 
x x x 
0 
x x x x x 
0 
x x 
0 
x x x x x x 0 x  0 
x x x x x x x 
0 
0 
1 1 1 1 1 1 1 1  1 
9.7.3 OR 
Function block diagram 
 
 
General description 
The output is High if any one of the evaluated inputs is High. Up to eight inputs are 
evaluated. 
Example: If eight light curtains are attached to the inputs of the function block, the 
output would become High as soon as at least one of the light curtains is free. 
Parameters of the function block 
Parameter  Possible values 
Number of inputs 
2 to 8 
Invert input x 
Each input of this function block can be inverted (see Section 9.5.2). 
 
Truth table 
The following applies for the truth tables in this section: 
“0” means logic Low. 
“1” means logic High. 
“x” means “any” = “0” or “1”. 
Truth table for OR evaluation with one input 
Input 1  Output 1
0  0 
1  1 
 
Table 24: 
Truth table for AND 
evaluation with eight inputs 
Figure 101: 
Function block diagram for 
the OR function block 
Table 25: 
Parameters of the OR 
function block 
Table 26: 
Truth table for OR 
evaluation with one input