12.05.2014 Views

Automating Manufacturing Systems - Process Control and ...

Automating Manufacturing Systems - Process Control and ...

Automating Manufacturing Systems - Process Control and ...

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

plc advanced functions - 16.20<br />

STA<br />

B<br />

D<br />

STC<br />

A<br />

C<br />

STB<br />

light_0 = STA<br />

light_1 = STB<br />

light_2 = STC<br />

first scan<br />

Figure 16.19<br />

A State Diagram<br />

The main program for the state diagram is shown in Figure 16.20. This program is<br />

stored in the MainProgram so that it is run by default. The first rung in the program resets<br />

the states so that the first scan state is on, while the other states are turned off. The following<br />

logic will call the subroutine for each state. The logic that uses the current state is<br />

placed in the main program. It is also possible to put this logic in the state subroutines.<br />

www.PA<strong>Control</strong>.com

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!