Step7 siemens S7

I'm starting to use step7 for the first time, just practising navigating and writing simple ladder programs and testing the different languages for my training manual. How does the absolute and symbolic addressing work? What do the symbols I, Q, mean etc? And how are the contacts typically represented as i have been using I0.0, I0.1 Q1.0 for the inputs and outputs, not knowing what they represent. Also by inputting these absolute addresses into a symbol table and given them a symbolic name, is that how to properly name your functions. I'm very new to all this and i only have a few basic documents to work from.

Thanks

Tom

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Alea Jacta Est

Tom

I means an input (I0.0)
Q means an output (Q0.0)
M means a memory bit (internal) (M0.0)
T means a timer (T1)
C means a counter (C1)

In the symbol table if you put I0.0 as symbolic name SWITCH1, and save the table then when you are writing your ladder instead of assigning a -| |- or -|/|- as I0.0 you can just write SWITCH1, I find this easier to do then trying to remember what each input or output is assigned to.

Just remember to have the 'symbolic representation' turned on in the 'View', 'Display With'

If you want to know any more, please clarify your question and I will do my best to answer you.

Have a search at Siemens A & D Support Web Site for some more manuals.

Paul

These may help

Chapter 3 explains absolute and symbolic addressing, the attached picture is an example.
Working with Step 7

This explains about using Step 7 to create blocks etc and setting up communications.
Simtic Programming with Step 7

Hello Tom,

Also you can program in German Symbolic, it´s mean the moore use arround the world, I recomend you to use it.

E means an input (E0.0)
A means an output (A0.0)
M means a memory bit (internal) (M0.0)
T means a timer (T1)
Z means a counter (Z1)

You can use also the tipical absolute and symbolic addressing, it´s mean one input for example a Push Bottom "Start" can call "start" or E0.0, depends to your favorite deside.

J ust remember to have the 'symbolic representation' turned on in the 'View', 'Display With'.

I recomend you to will start to learn the basic code by STL (AWL) to improve in this type of PLC.

Best reagards

Tony