Siemens SIMATIC S7-200 System Manual page 27

Entering Network 3: Resetting the Timer
When the timer reaches the preset value (100) and turns the timer bit on, the contact for T33 turns
on. Power flow from this contact turns on the M0.0 memory location. Because the timer is enabled
by a Normally Closed contact for M0.0, changing the state of M0.0 from off (0) to on (1) resets the
timer.
To enter the contact for the timer bit of
T33:
1. Select the Normally Open contact
from the bit logic instructions.
2. Hold down the left mouse button
and drag the contact onto the third
network.
3. Click on the "???" above the
contact and enter the address of
the timer bit: T33
4. 4. Press the Return key to enter the Press the Return key to enter the
address for the contact.
To enter the coil for turning on M0.0:
1. Select the output coil from the bit logic instructions.
2. Hold down the left mouse button and drag the output coil onto the third network.
3. Double-click the "???" above the coil and enter the following address: M0.0
4. Press the Return key to enter the address for the coil.
Saving the Sample Project
After entering the three networks of instructions, you have finished entering the program. When
you save the program, you create a project that includes the S7-200 CPU type and other
parameters. To save the project:
1. Select the File > Save As menu
command from the menu bar.
2. Enter a name for the project in the
Save As dialog box.
3. Click OK to save the project.
After saving the project, you can
download the program to the S7-200.
Getting Started
Figure 2-9 Network 3
Figure 2-10 Saving the Example Program
Chapter 2
13