1, find a good book to read, recommend Liao Changchu's book and Siemens' Cui Jian's book, but don't read the book to death, just look through the hardware part. The hardware part focuses on the system structure, the relationship between hardware and software, and the key is software programming (I didn't have any information when I learned s7 programming, so I just read online help when I used any instructions).

2. Another good material is the official training ppt uploaded by Siemens from the Internet, which is very long and detailed, and this can also be viewed.

3, the software to the next step 7 professional version (with simulator plcsim), so that you can program and simulate running tests in the computer, familiar with various basic instructions.

4, give yourself some small topics, such as traffic lights, motor forward and backward, answering machine and so on. And use several methods to achieve it.

5. Read more posts in the industrial control forum.

6. Don't be limited to ladder programming. Statement table and SCL are worth learning.

7. Don't be limited to PLC programming language, learn a high-level language programming such as VB, and experience the programming ideas of high-level language, which is of great benefit to PLC programming in the future (some people are buried in PLC all their lives, and their eyes can't see far after all, you should know that the openness of step7 is beyond your imagination).

Generally speaking, after 2-3 years of engineering, you can basically reach a relatively proficient level (this can be achieved by almost everyone), and then there will be differences (this is mainly caused by differences in computer knowledge, and people who are good at computers can often reach a certain level of plc programming). If you want to improve, it depends on your own understanding and opportunities (good projects or expert advice).

I hope I can help you.