Introduction to Industrial Automation

Figure 4.9  A state diagram where the states constitute de-energizing signals (electrical latching).

    

R

b

0

C

2

C

1

s

1

2

3

N

C

1

C

1

b

1

C

2

C

2

C

1

s

C

2

Figure 4.10  Logical design of an automation circuit including electrical latching and sensory 

command.

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  Introduction to Industrial Automation

instantaneous but is of the general type “operation as long as the signal is ON”, then for the formula 

(1) in Step 4, the last term of “current state of variable” should be omitted.

In the following example, the utilization of the state diagram method by means of a “state 

machine” technique for the automation of an industrial process machine with multiple states 

will be presented. In this case, the introduction of complementary auxiliary variables will also 

be presented, which actually introduces the auxiliary relays in an industrial automation circuit. 

Finally, it should be noted that the necessity of utilizing auxiliary relays for implementation of an 

“automation logic” have also been presented in Chapter 3.