Siemens PLC Learning Bottleneck 50

The problem you encounter now is something I have experienced when I used to study on my own, I used to buy a ** of technical success, I can only read it for a year, and I bought a lot of books, and I look at it Sometimes I doze off, sometimes I encounter a problem, although I have a friend who is an engineer and can occasionally answer it, but it is not good to trouble people often, and then I don't want to learn when I learn to learn, and there was no equipment practice at that time, and I didn't learn again for several months, and then it was a colleague of mine, who used to be an electrician together, He learned from Bojun PLC, at that time his monthly salary was more than nine k, and then I also went to study, and now I am also an engineer, and I also take on some projects in my spare time, which is not bad.

PLC200 is not mainstream at present, if you want to learn PLC, it is recommended to start with 300, because 400, 1200 are written similarly. 200 mainly uses a ladder chart, which should be well understood. Compare, shift instruction I remember 200 in the help, the comparison instruction is equivalent to a condition, greater than less than or equal to, after the condition is met, run the next instruction.

The shift is stored in that place (I can't remember exactly) because some of the data is only available in a specific place. Addressing you need to know the place, like i q m aiq aiw, and know where each data should be used, something like that. If you have the conditions, you can still sign up for a class, I am taught in school, and I still feel that 200 is too backward after coming out, and industrial automation is 1200 to start, so learn slowly.

The shift moves the "bit", and the comparison command compares the size of the value stored in the address variable.

1.If multiple wires need to be connected to the common end, you can use the method of connecting in series, such as 1 to 2, 2 to 3 ......In this way, the port only needs to be connected to 2 wires.

The stl is ld, which means that a signal of 1 is pressed into the stack point, because whether the subsequent program is executed depends entirely on whether the top of the stack is 1

It should be scr, and I feel that since there is no output, scanning is meaningless. SCR is the whole program segment, and PLC can only execute the program within the segment. Jump commands are much more flexible, not only imitating the function of SCR (which can be executed in segments within a certain program), but also using jumps to achieve other functions.

1. In practice, there are terminal blocks, and short splice pieces can be used between terminal blocks, so one wire is connected if there is.

The output is not allowed to be directly connected to the left bus, so it must be used.

3. The existence of MCR instructions is to be compatible with early PLC programs, and there are no subroutines in early PLCs, in fact, MCR instructions are almost not used now.

1.Generally, this is not possible, because PLCs are all several points and one common end. Even if you want to pick up so much, you can merge externally and then connect to the public side.

2.Because the output cannot be connected to the busbar, it should be used.

The instructions are used on Mitsubishi PLC, and they are used for linear programming.

The recommended answer should be in parallel, and then connected to the terminal block, or to the shunt bar.

There are "In-Depth Explanation" tutorials, which can be purchased in bookstores or online.

2.Ask Siemens for a selection manual.

3.Attend specialized training sessions.

5.Learn from the Siemens Forum.

6.Practice more

You can send me your email address and I'll send you some information.

The integer and double integer multiplication (mul) command multiplies two 16-bit integers to give a 32-bit product.

The result of this instruction is that it requires a two-word memory (32 bits) to be used for storage, so the memory has to be written vd4 (the specification of the instruction).

The Multiply by Integer (mul-i) command multiplies two 16-bit integers together and produces a 16-bit product.

The result of this instruction can only be stored in a word memory (16 bits), which is also specified in the instruction.

To learn PLC, it is necessary to master the basic knowledge of electrical engineering and basic knowledge of computers, so that it is faster to learn, and at the same time, Siemens PLC will be especially used in place, bytes, words, and double words, so the foundation of this part must be solid.