Page 223 - Programmable Logic Controllers, Fifth Edition

L1 Inputs Ladder logic program Outputs L2
S1
1 MCR
S1 PL1
S2 PL1
S2 2
PL2
S3 S3 PL2
3 L
S4
S4 PL2
4 U
S5

S6 5 MCR
S5
6 MCR

S6 TON
TIMER ON DELAY
7 EN
Timer T4:1
Time base 1:0 DN
Preset 10
Accumulated 0

8 MCR

Figure 9-29 Program for Problem 1.

Inputs Ladder logic program Outputs
RTO type instead of a TON, what would happen S1 PL3 L2
to the accumulated value? L1
1
2. Answer the questions, in sequence, for the jump-to-
label program in Figure 9-30. Assume all switches S1 S2 10 PL1
are turned off after each operation.
a. Switch S3 is turned on. Will output PL1 be ener- S2 2 JMP
gized? Why? S3 PL1 PL2
b. Switch S2 is turned on first, then switch S5 S3
is turned on. Will output PL4 be energized? 3
Why? S4 S5 PL3
c. Switch S3 is turned on and output PL1 is ener- PL4
gized. Next, switch S2 is turned on. Will output 4
PL1 be energized or de-energized after turning S5 PL4
on switch S2? Why? 10 S4 PL2
d. All switches are turned on in order according 5 LBL
to the following sequence: S1, S2, S3, S5, S4.
Which pilot lights will turn on? Figure 9-30 Program for Problem 2.

204 Chapter 9 Program Control Instructions

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