simatic s7 300

hi. I cannot find in siemens' manuals the adresses of memory bits (and their types) for a S7 314C-2DP PLC. also, it will be very useful for me if someone can dirrect me to some free e-documentation (tutorials) about this subjet. learning from manuals is very difficult. thank you.

Hello egergely;

For your 1st question:


This means your memory (flag) bits/bytes area goes from M0.0 to M255.7.
You can read/write to this ares in different formats:
-bit, as M23.5
-byte, as MB56
-word, as MW204
-double-word, as MD46
And if you attribute a symbolic name to your registers, you can use different alternate formats as well (a byte flag can be used as a byte (0-255 numetical value) or as a char (ASCII caracter) for example).

For your second question: here is a link to S7-300 tutorials, also from Siemens; have a look, if you have more questions after studying them come back to the forum.

http://www.automation.siemens.com/fea/html_76/down_module.htm

Hope this helps,
Daniel Chartier