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Automating Manufacturing Systems - Process Control and ...

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plc memory - 14.13<br />

onds after it has been turned on. The light should flash once a second.<br />

6. How many words are required for timer <strong>and</strong> counter memory?<br />

14.7 PRACTICE PROBLEM SOLUTIONS<br />

1. both are similar. The timer <strong>and</strong> counter memories both use double words for the accumulator<br />

<strong>and</strong> presets, <strong>and</strong> they use bits to track the status of the functions. These bits are somewhat different,<br />

but parallel in function.<br />

2. Inputs cannot be changed by the program, <strong>and</strong> some of the status bits/words cannot be changed<br />

by the user.<br />

3.<br />

door open<br />

seat belt connected<br />

Inputs<br />

door open<br />

seat belt connected<br />

key on<br />

key on<br />

Outputs<br />

buzzer<br />

light<br />

TON<br />

Timer t_remind<br />

Delay 5s<br />

t_remind.TT<br />

door open<br />

buzzer<br />

TOF<br />

Timer t_light<br />

Delay 10s<br />

t_light.DN<br />

key on<br />

light<br />

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

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