Turning The Led On And Off - Siemens Simatic S7-200 CPU 210 System Manual

Getting Started with a Sample Program

Turning the LED On and Off

The program uses a timer (T1) and the pattern stored in MW3 to turn the LED on and off. The
program increments MW1 to count the number of passes through the control logic for flashing
the lights; after 10 passes, the MW1 is reset to 0.
Figure 3-25 shows the control logic for starting the timer. The timer starts when the system is
armed, the light-blink timer bit is not set, and either Zone 1 or Zone 2 opens.
Network 9 If the light-blink timer bit is not set, and the system is
armed, start the light-blink timer when either Zone 1 or
Zone 2 becomes open.
M0.7
/
Figure 3-25 Control Logic for Starting the Light-Blink Timer
Figure 3-26 shows the control logic for incrementing the count for the number of times that
the light-blink logic has been performed.
Network 10
T1
>=I
+4
Figure 3-26 Control Logic for Setting the Timer Bit and Incrementing the Counter
Figure 3-27 shows the control logic for turning the LED on and off. Each pass through the
light-blink logic evaluates a different bit of MW3 (M4.0 to M4.7). Based on the pattern loaded
(see Figure 3-24), the LED turns on or off.
Figure 3-28 shows the control logic for resetting the count.
3-26
LAD
I0.2 I0.0
/ / IN
+0 PT
I0.1
/
LAD
If the light-blink timer is less than or
equal to 400 ms, then set the light-blink
M0.7
timer bit, reset the LED bit, and
increment the step counter.
M0.0
R
1
INC_W
EN
MW1 IN OUT MW1
NETWORK
LDN
AN
LDN
T1
ON
TON
TON
NETWORK
LDW>=
=
R
INCW
S7-200 Programmable Controller, CPU 210
C79000-G7076-C235-01
STL
M0.7
I0.2
I0.0
I0.1
T1, +0
STL
T1, +4
M0.7
M0.0, 1
MW1