Page 169 - Programmable Logic Controllers, Fifth Edition

Ladder logic program
Outputs
L1
T4:2 TON
TIMER ON DELAY EN
Timer T4:0 North/south
DN Time base 1.0 tra c lights
Preset 30 DN
Accumulated 0 Red Red
North/south
T4:0 TON
TIMER ON DELAY EN
Timer T4:1 Amber
DN Time base 1.0 North/south Amber
Preset 25 DN
Accumulated 0
Green
T4:1 TON North/south Green
TIMER ON DELAY EN
Timer T4:2
DN Time base 1.0
Preset 5 DN
Accumulated 0
T4:0 TON
TIMER ON DELAY EN
Timer T4:3
EN Time base 1.0
Preset 25 DN
Accumulated 0
T4:0 T4:0 Red

EN DN North/south
East/west
T4:1 T4:1 Green
tra c lights
EN DN North/south Red Red
T4:2 T4:2 Amber East/west

EN DN North/south Amber Amber
East/west
T4:3 T4:3 Green
Green Green
EN DN East/west East/west
T4:3 T4:0 Amber

DN DN East/west
T4:0 Red

DN East/west
Figure 7-37 Control of traffic lights in two directions.

150 Chapter 7 Programming Timers

pet73842_ch07_131-155.indd 150 05/11/15 4:22 PM