Page 211 - Programmable Logic Controllers, Fifth Edition

Pilot light

Solenoid

Weight
sensor

(a)
Main program
Inputs file 2 Outputs
Sensor JSR
L1 JUMP-TO-SUBROUTINE L2
SBR file number U:3

Sensor PL1 Motor M1
OFF/ON

T4:1/EN
Stop PL1 PL1
Stop Start Motor

Start
Motor SOL

Sensor
OFF/ON Sensor SOL

Subroutine
file 3
TON
SBR T4:1/DN TIMER ON DELAY
SUBROUTINE Timer T4:0 EN
Time base 1.0 DN
Preset 1
Accumulated 0

T4:0/DN TON
TIMER ON DELAY
Timer T4:1 EN
Time base 1.0 DN
Preset 1
Accumulated 0
RET
RETURN
(b)
Figure 9-11 Flashing pilot light subroutine. (a) Process. (b) Program.

192 Chapter 9 Program Control Instructions

pet73842_ch09_184-206.indd 192 03/11/15 4:01 PM