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operators:AND, OR, and NOT.The AND operator has two inputs and one output. With
two binary values, you can have four possible value combinations: 00, 01, 10, 11.Table 1.3
shows the results of ANDing two values. In English,Table 1.3 states “Input 1 AND Input
2 must both be 1 to get 1 as a output, otherwise the output is 0.”

Table 1.3 Truth Table for the AND Operator

Input 1 Input 2 AND
0 0 0
0 1 0
1 0 0
1 1 1

NOTE
In mathematical theory the AND, OR, and NOT operations are referred to as
operators. When implemented in a mechanical design the device that performs
these operations are referred to as gates.

The AND Gate

Let’s take a moment and look at PneumADDic II’s AND Gate sub-assembly, as can be
seen in Figure 1.7.The AND Gate is composed of two pistons that act as inputs.The two
pistons are connected to the pneumatic switch in the gate that plays the role of the
output.

Figure 1.7 The Pneumatic AND Gate

Input 1 Input 2

Output

In Figure 1.8, you can see four pneumatic AND Gate sub-assemblies showing each of
the possible input states described in Table 1.3. Notice what happens to the handle of the
pneumatic switch as the inputs change to different values. When both of the pistons are
expanded, the switch is flipped to the right (what is considered the 1 position). In all
other cases, the switched is flipped to the left (what is considered the 0 position).