Chapter 9
128
Logic programming – Function blocks
9.7.2 AND
Function block diagram
General description
The output is High if all evaluated inputs are High. Up to eight inputs are evaluated.
Example: If eight emergency stop buttons are attached to the inputs of the function
block, the output would become Low as soon as one of the emergency stop buttons is
pressed.
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 AND evaluation with one input
Input 1 Output 1
0 0
1 1
Truth table for AND evaluation with two inputs
Input 1 Input 2 Output 1
0
x
0
x
0 0
1 1 1
Figure 100:
Function block diagram for
the AND function block
Table 21:
Parameters of the AND
function block
Table 22:
Truth table for AND
evaluation with one input
Table 23:
Truth table for AND
evaluation with two inputs
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