S7-300 question?

Hello,everyone!

I'm new to PLC. Today I got a s7-300 program. In its Block OB1, there is a "move" command in the first network. The data at 'IN' is 'QW32',and the data at 'OUT' is 'DB3.DBW108'.

my question is : 1 what and where is 'QW32'?
2 what and where is 'DB3.DBW108'?
3 what does 32 means?

These are basic questions, so I would suggest getting hold of a good book. Hans Berger has written a couple on the S7 range. ISBN 3895780936 is the STL version but as a beginner the LAD version may be more appropriate.

Your questions

1. QW32 is output word 32. Consisting of real-world outputs Q32.0 to Q33.7 (16 bits)

2. Part of the S7's memory is accessible via DATA BLOCKS (DB). DB3 addresses a data block, and DBW108 addresses word 108 in that block.
The 'W' indicates WORD i.e. 16 bits. You can also access DBX (bit) DBB (byte) or DBD (double word).

Thanks!

Thank you very much for your reply!

You tell me that the real-world output Q32.0~Q33.7, does these output address in relation with hardware,the output module?

Can you tell me where can I buy that book? how? I'm living in China,too far away.


Does DBW108 mean the NO.108 word?

Wait for your reply! Thanks again!

Q32.0 to Q33.7 probably relate to an output module.
Have a look in the 'Hardware Configuration' and it will tell you what modules are installed and their addresses.
You are right about 108.
Don't know where you can get the book from - Amazon.com ? Or Siemens themselves - they must have offices in China.

good luck