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2 Simple Application Controllers
The Logic Function Blocks 5
5 - 3
5.2
The OR Block
The Output comes ON when any input is ON.
The Output remains OFF only if all the inputs are OFF.
Unused Inputs are considered to be OFF
Table 5.3: OR Logic gate
Input 1
Input 2
Input 3
Input 4
Output
On
On
On
On
On
On
On
On
Off
On
On
On
Off
On
On
On
Off
On
On
On
Off
On
On
On
On
On
On
Off
Off
On
On
Off
On
Off
On
On
Off
Off
On
On
Off
On
On
Off
On
Off
On
Off
On
On
Off
Off
On
On
On
On
Off
Off
Off
On
Off
On
Off
Off
On
Off
Off
On
Off
On
Off
Off
Off
On
On
Off
Off
Off
Off
Off
0 0
O R
2
3
O
4
1
01
OR
Output
1
2
3
4
