15 decide whether each of these statements is true t

15. Decide whether each of these statements is true (T) or false (F). With no input

to X002 in Figure 9.23:
(i) The output Y021 is switched on 20 s after the input X001.
(ii) The output Y020 is switched off 20 s after the input X001.
Problems 16 through 19 refer to Figure 9.24, which shows an Allen-Bradley program,
and Figure 9.25, which shows a number of time charts for a particular signal input
to I:012/01.
f09-24-9780128029299
FIGURE 9.24 Diagram for Problems 16 through 19.
f09-25-9780128029299
FIGURE 9.25 Diagram for Problems 16 through 19.
16. For the input shown in Figure 9.24, which is the output from O:013/01 in Figure
9.25?
17. For the input shown in Figure 9.24, which is the output from O:013/02 in Figure
9.25?
18. For the input shown in Figure 9.24, which is the output from O:013/03 in Figure
9.25?
19. For the input shown in Figure 9.24, which is the output from O:013/04 in Figure
9.25?
20. Decide whether each of these statements is true (T) or false (F). For the
ladder program in Figure 9.26, with the timer set to 5 s, when there is an input to
In 1:
f09-26-9780128029299
FIGURE 9.26 Diagram for Problem 20.
(i) Out 1 is immediately activated.
(ii) Out 2 is activated after 5 s.
21. Decide whether each of these statements is true (T) or false (F). For the
ladder program in Figure 9.27, with both timers set to 10 s, when there is an input
to In 1:
f09-27-9780128029299
FIGURE 9.27 Diagram for Problem 21.
(i) Out 1 is activated 20 s after the input occurs.

(ii) Out 1 is activated for a time of 20 s.
22. Devise ladder programs for systems that will carry out the following tasks:
(a) Switch on an output 5 s after receiving an input and keep it on for the
duration of that input.
(b) Switch on an output for the duration of the input and then keep it on for a
further 5 s.
(c) Switch on an output for 5 s after the start of an input signal.
(d) Start a machine if switch B is closed within 0.5 s of switch A being closed;
otherwise the machine is not switched on.
Lookup Tasks
23. Look up the timers available for a particular range of PLCs.