Introduction to Industrial Automation

Figure 3.9  Periodic operation of a machine.

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Industrial Automation Synthesis 

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3.2.7   Operation of Two Machines with a Common Manual 

Command or Separate Automatic Commands

In an industrial environment, there are a lot of cases where the same process is supported by two 

machines. For example, consider a liquid extracted from a tank by the utilization of two pumps, 

parts that are being forwarded from one station to another through a double conveyor belt system 

and two machines that are packaging parts that are coming from a process station at the same 

time. In the case of an automatic operation of two such machines, it is straightforward that these 

machines will operate through commands provided by the utilization of sensors. Moreover, in case 

of faults, it is ideal to have the ability to operate these machines in a manual mode, overriding the 

sensory commands. In this particular case, we will also assume that there is a demand for having 

the two machines operate each other with a separate automatic command or both with the same 

manual command, after an initial selection of the desired state. In Figure 3.11, the corresponding 

N

C

50 Hz 230 V

R

e

RS

1-0-2

Stop

Start

C

‘H’

‘A’

1

2

T

T

24 h

24-hour

timer switch

(b)

N

C

50 Hz 230 V

R

e

RS

1-0-2

Stop

Start

C

‘H’

‘A’

Automatic

operation

command

1

2

(a)