PLC Siemens S7 300 400

Differences: The difference between S7200 and S7300 400 is quite large, which is reflected in the instruction system, program structure, and programming software.

The S7200 is designed for use in low-performance control systems, while the S7300 is a medium-sized PLC that can be expanded with 32 modules. The S7400 is a large PLC that can be expanded with more than 300 modules.

At present, there are many PLC manufacturers, and the most widely used in China are Siemens AB omron ...However, the typical PLC that emphasizes structured programming is Siemens, and Siemens' industrial automation and industrial communication fields are recognized by countries around the world, so it is recommended that you learn from Siemens.

There is a book from beginner to proficient Siemens S7300-400PLC technology and application It's very good It may be out of print now Look for it.

I'm also a beginner, so I'll talk a lot when I have time.

S7-300 or S7-400 and S7-200 From the application aspect, S7-200 is small and has few processing points, and S7-300 and S7-400 are medium and large PLC modules.

In terms of cost, the S7-200 is cheap and suitable for small equipment, while the S7-300 and S7-400** are higher;

In terms of configuration and programming, the S7-200 is easy to use, but it does not have as many functions as the S7-300 and S7-400.

From beginner to proficient in Siemens S7300-400PLC technology and application > Liao Changchu's, very good. Siemens' network capabilities are the biggest advantage. A single product may not be outstanding, but networking to complete a project is Siemens' biggest advantage.

The S7-200 is small-scale.

S7-300 S7-400 is massive.

China Industrial Control Network is the best to learn.

The resources are good PLC programming learning, or the combination of theory and practice, based on practical operations, so that you can master the programming method faster.

First, the design is different.

1. PLC200: Adopt institutional design. The computing speed is lower than that of PLC300.

2. PLC300: Modular structure, with high-speed instruction speed. Floating-point arithmetic operations are more efficient for more complex arithmetic operations.

Second, the mode of operation is different.

1. PLC200: no human-machine interface service.

2. PLC300: software tool with standard user interface is convenient for users to assign parameters to all modules; Convenient human-machine interface services.

Third, the operating system is different.

1. PLC200: equipped with an operation mode selection switch, the operation mode selection switch can be pulled out like a key, when the key is pulled out, the operation mode can not be changed, so as to prevent illegal deletion or rewriting of user programs.

2. PLC300: the operating system automatically processes the transmission of data; The CPU's intelligent diagnostic system continuously monitors whether the system is functioning properly, logging errors and special system events (e.g., timeouts, module replacements, etc.); Multi-level password protection allows users to highly and effectively protect their technical secrets from unauthorized copying and modification.