288 Programmable Logic Controllers: Hardware and Programming
Example 13-5
The diagram in Figure 13-15 demonstrates how to use a timer
on delay (TON) function and a bit shift left (BSL) function to turn on
and off lights in ascending order every three seconds. The timer on
delay controls the bit shift left function, which moves a bit through
000
End
T4:0/DN
007
EN
DN
TON
Timer On Delay
Timer T4:0
Time Base 0.1
Preset 30
Accum 6
001
EN
DN
BSL
Bit Shift Left
File #B3:0
Control R6:0
Bit Address B3:0/0
Length 4
002
R6:0/UL
I:1/0
Start
T4:0/DN
B3:0/0
003
B3:0/0 O:2/0
GLT
004
B3:0/1 O:2/1
WLT
005
B3:0/2 O:2/2
RLT
Reset
006
I:1/1 R6:0
RES
Figure 13-15. PLC ladder logic diagram and binary table for Example 13-5. Using the bit shift left
function to turn on and off three lights in ascending order.