How To Program A Siemens S7-300 Programmable Logic Controller

Do you have a Siemens S7-300 Programmable Logic#2.) 
Controller that you are not familiar with but you needWhen you release the mouse button over slot #2, a
to program it NOW!  Following is a quick set ofnew window will open, “Properties –
instructions I have put together to help you getPROFIBUS interface”.  Click new, a new window
started programming a Siemens S7-300 PLC.  I haveopens, click Ok, and then click OK again.  We are
these same instructions with pictures on my websitenot setting up a network at this time. 
at  You will now see your CPU and associated hardware
After loading the programming software andlisted. 
connecting a Siemens MPI cable between yourDouble click in the Slot that list your DI16/DO16
programming computer and the PLC, open SIMATIC(Digital Input/Digital Output). 
Manager by clicking the icon on the desktop.  TheA window with three tabs will open.  The first tab
STEP 7 Wizard: “New Project” window willwill be General, the second tab will be Addresses and
open.  It is easier to use the Wizard to setupthe third tab will be Inputs. 
communications with your PLC, but I chose to takeOpen the tab “Addresses”.  We need to
the scenic route.  I figured I would learn more thischange the default addresses.  Do this by
way.  So, close the STEP 7 Wizard window byunchecking the System Default button and changing
clicking Cancel.  If there are any other windows or124 (or whatever address you have) to 0.  Do this
projects open, close them.  We want to start withfor both the Inputs and Outputs. 
a totally new program.We now need to change the Node Address.  Go
Create a new project by clicking the new projectback to the window where you double clicked DI16
button on the toolbar in the upper left corner of yourDO16 and double click in Slot 2, the CPU 313-2DP
screen. slot. 
The New Project window opens.  Here you will seeThe Properties – CPU 313C-2DP window will
any existing programs located on your computer. open. 
Near the bottom of the window, you will see theLook down the window a little over half way and
Name: input form.  Type whatever you want tofind the Interface area and click on Properties.
name your new project and click OAnother window, “Properties – MPI interface
A new window will open showing the name of yourCPU 313-2DP” will open.
project at the top.  You will also see your project inChange the address to meet your specific criteria.  I
the window on the left hand side of the screen atknow that my laptop, which I am using to program
the top.  Right click your project and choosemy PLC, is always addressed as 1 and my target PLC
“Insert New Object”.  Choose the deviceis usually addressed as 2.  You will probably be the
you will be programming.  We will be using thesame.  
SIMATIC 300 Station so choose that selection. Now click MPI(1) and click OK.  Click OK again to
You will now see SIMATIC 300 appear in the rightclose the Properties window.
window of your screen.  It should be highlightedSave and Compile by clicking the icon located on the
blue.  Click anywhere in the window to make theleft of the toolbar. 
blue go away.   Double click SIMATIC 300 and it willDownload the hardware configuration to the PLC by
move to the left window and “Hardware” willclicking the download icon located on the toolbar. 
appear in the right window. A window titled “Select Target Module”
Double click “Hardware” and two (maybeshould open. Click OK.  
three) new windows will open.  On the left will beAnother window titled “Select Node
SIMATIC 300 – (the name of your project). Address” will open.  You should see listed your
The window on the right will be the catalog ofnode address for the PLC you are working with as
parts. you configured it in a previous step.  If not, click
Look in the right window, the parts catalog, and clickview and click on whatever node address appears
the plus sign beside SIMATIC 300.and click OK.
Click the plus sign beside RACK – 300.  Click andSwitch back to SIMATIC manager (by clicking the
drag the Rail onto the left window.  You will nowtab on the taskbar).
see the Slots window appear.  This is where we willClick on Options.  Choose Set PG/PC Interface. 
place our PLC componentsChoose PC Adapter (Auto). 
We will first choose our CPU.  Looking at the partsClick Properties.  A new window will open, displaying
catalog, in the SIMATIC 300 tree, choose the CPUeither Automatic Bus Profile Detection or Local
that you are using.  We are using the CPU – 300Connection.  Click Local Connection and choose
so click the plus sign beside that choice. USB.  Now choose Automatic Bus Profile Detection
Now look at the front top left of your PLC.  This isand change the address to 30.  You can check your
where you will find the PLC model.  I will useconnection now by clicking Start Network
CPU313C-2 DP as an example since this is the modelDetection.  If a new window opens displaying
PLC that I use. Network Type = MPI, Transmission Rate =
Find this CPU in your parts catalog and click the plus187.5kbps,  you have established communications
sign.  You will now see some part numbers. with your S7-300.  Click Close.  Click OK.  Click
Look back at your PLC.  Locate the door coveringOK. 
the MPI port.  This will be the bottom left side ofIt is now time to start programming.  Looking at the
the PLC.   At the bottom of the door you will findSIMATIC Manager window, click the plus sign located
the part number.  The part number for the PLC Ibeside SIMATIC 300(1), click the plus sign beside CPU
am using as an example is 313-6CF03-0AB0.  313C-2DP, click the plus sign beside S7 Program(1).
Find this part number in the parts catalog.  You willNow click on Blocks and you will see System data
notice this is another folder.  Open it and you willand OB1 appear in the right window on your screen. 
see V2.0 and V2.6.  Look back at the PLC, open theDouble click on OB1 and a new window will open
door covering the MPI port, and right above the MPInamed Properties – Organization Block 
port you will see V2.6.3. Here you can choose how you want to program, in
Go back to the parts catalog and click V2.6.  NoticeLAD (ladder), STL (statement list), or FBD (function
how a slot in the left hand window will highlightblock diagram).  Choose which you want to use and
green.  I believe it will be slot #2.  (Slot #1 isclick OK.
reserved for power supplies.)  This is where you willDouble click OB1 again and the LAD/STL/FBD
drag and drop your CPU.  (Notice the software willprogramming window will open. 
not let you put the CPU in any other slot but slotYou can now start programming.