What are the product categories of Siemens PLC

Programmable controllers are programmable controllers generated from modern production needs, and their classification must definitely meet the needs of modern production. Generally speaking, programmable controllers can be classified from three perspectives. One is to classify based on the control scale of programmable controllers, the second is to classify based on the performance level of programmable controllers, and the third is to classify based on the structural characteristics of programmable controllers.

1、 Classified by control scale:

It can be divided into mainframe, mid size, and small size machines.

Mini computer: The control points of a mini computer are generally within 256 points, suitable for single machine control or small system control.

Siemens mini computers have S7-200: processing speed of 0.8~1.2ms, memory of 2k, digital quantity of 248 points, and analog quantity of 35 channels.

Medium size machine: The control points of a medium size machine are generally not greater than 2048 points and can be used for direct control of equipment. It can also monitor multiple lower level programmable controllers, making it suitable for control of medium or large control systems.

Siemens medium-sized computer has S7-300: processing speed 0.8~1.2ms, memory 2k, digital quantity 1024 points, analog quantity 128 channels, network PROFIBU, Industrial Ethernet, MPI.

Mainframe: The control point of a mainframe is generally greater than 2048 points, which can not only complete complex arithmetic operations but also perform complex matrix operations. It can not only be used for direct control of devices, but also for monitoring multiple lower level programmable controllers.

Siemens mainframe has S7-400: processing speed of 0.3ms/1k words, memory of 512k, and I/O points of 12672.

2、 Classified by control performance:

It can be divided into high-end machines, mid-range machines, and low-end machines.

Low-end machine

This type of programmable controller has basic control functions and general computing power. The working speed is relatively low, and the number of input and output modules that can be carried is relatively small.

For example, the S7-200 produced by SIEMENS in Germany belongs to this category.

Mid range machine

This type of programmable controller has strong control functions and strong computing power. It can not only complete general logic operations, but also complete more complex Trigonometric functions, exponent and PID operations. The working speed is relatively fast, and the number of input and output modules that can be carried is also quite large, and there are also many types of input and output modules.

For example, the S7-300 produced by SIEMENS in Germany belongs to this category.

High end machine

This type of programmable controller has powerful control functions and computing power. It can not only perform logic operation, Trigonometric functions operation, exponential operation and PID operation, but also perform complex matrix operation. The working speed is very fast, and there are a large number of input and output modules that can be carried. The types of input and output modules are also very comprehensive. This type of programmable controller can complete large-scale control tasks. Generally used as the main station in networking.

For example, the S7-400 produced by SIEMENS in Germany belongs to this category.

3、 Classification by structure:

Integral

The integrated programmable controller integrates the power supply, CPU, memory, and I/O system into one unit, which is called the basic unit. A basic unit is a complete PLC.

When the control points do not meet the requirements, an expansion unit can be connected again. The characteristics of the integrated structure are very compact, small size, low cost, and convenient installation.

Combined

A modular programmable controller divides the various components of a PLC system into several modules according to their functions, such as CPU module, input module, output module, power module, and so on. The functions of each module are relatively simple, but the types of modules are increasingly rich. For example, some programmable controllers, in addition to basic I/O modules, also have some special functional modules, such as temperature detection module, position detection module, PID control module, communication module, and so on. The characteristic of a modular PLC is that the CPU, input, and output are all independent modules. Unified module size, neat installation, free selection of I/O points, convenient installation, debugging, expansion, and maintenance.

Stacked type

The stacked structure combines the advantages of compact, small size, and easy installation of the overall structure, as well as the flexible and neat installation of the I/O points in the combined structure. It is also composed of combinations of various units. Its characteristic is that the CPU is an independent basic unit (composed of the CPU and certain I/O points), and other I/O modules are expansion units. During installation, there is no need for a substrate, only cables are used for connection between units, and each unit can be stacked one by one. Enable the system to achieve flexible configuration and compact size.