Siemens Simatic S7-200 CPU 210 System Manual page 58

Getting Started with a Sample Program
Refer to Figure 3-18 and follow these steps to enter the two contacts on the second rung of
the first network:
1. Select "Contacts" from the family listing and select ">= Integer" from the instruction listing.
This inserts a comparison instruction at the cursor position. This instruction compares the
value of the notification timer (Alert_Timer) with the time value.
2. Type either the symbolic name Alert_Timer or the absolute address T0 in the
highlighted area. Pressing ENTER highlights the second value for the comparison.
3. Type 600 and press ENTER. This instruction becomes true (and turns on) when the timer
is greater than or equal to 600, which equals 60 seconds.
4. Click the F4 toolbar button to create a normally open contact. Type Armed (or I0.2) and
press ENTER.
Contacts
Network 1
"Panic_Alarm"
Select "Contacts" from
the family listing.
Contacts
Network 1
"Panic_Alarm"
VW0
>=I
VW0
Contacts
Network 1
"Panic_Alarm"
"Alert_Timer"
>=I
+600
Figure 3-18 Entering the Comparison Instruction and Next Contact
3-18
>= Integer
F2
Normally Open
Sound the alarm! Normally Closed
== Integer
>= Integer
<= Integer
Not
Positive Transition
Negative Transition
>= Integer
F2
Enter the address:
Sound the alarm!
T0
or
Press ENTER and then
Alert_Timer
enter the time value:
600
Normally Open
F2
Sound the alarm!
"Alarm_Bit"
S
1
"Armed"
F3
F4 F5 F6
Select ">= Integer" from the
instruction listing.
F3
F4 F5 F6
"Alarm_Bit"
S
1
F3
F4 F5 F6
Insert a normally open
contact and enter I0.2
( or Armed).
S7-200 Programmable Controller, CPU 210
C79000-G7076-C235-01
F7 F8 F10
F7 F8 F10
F7 F8 F10