Model selection of Siemens PLC

First, according to the process requirements:

Determine the number of input and output points, that is, Di, do, AI and AO

Determine the need for external communication interfaces, such as MPI, DP, Ethernet, etc

Determine which series to choose, such as S7-200, S7-300 and S7-400

Finally, determine and select the specific CPU model PLC

Note: the storage capacity is determined. Note that when the system has analog signals or needs to process a large amount of data, its storage capacity should be larger.

Model selection of Siemens PLC_ Siemens PLC model description

Siemens PLC model description

Naming rules of Siemens product order number:

Take 6ES7 221-0ba23-0xa0 as an example,

6es – automation system series

7 —— 7: S7 Series, 5: S5 series

2 —— 2:200 series, 3:300 series, 4:400 series

2 —— 1: CPU, 2: di / do, 3: AI / AO, 4: communication module, 5: function module

1 —— 1: input, 2: output, 3: input and output (for digital quantity)

1bf — input / output voltage level, type, number of points, etc. there are many, so it’s better to check the sample

22 —- version. If the last digit is different, it can be basically universal


So the above is the switching value input expansion module of 200

Complete order No. 6ES7 321-1bh01-0xa0

6ES7: PLC module of S7 Series

3: 300 series

2: Digital quantity (1 refers to CPU, 3 refers to analog quantity, 4 refers to communication and 5 refers to function)

1: Input (2 for output, 3 for input and output)

1: Function level (the greater the number, the stronger the function)

B: Transistor (H is relay, f is AC, if analog, K is universal, P is temperature signal)

H: 16 points, (L stands for 32 points, f for 8 points, D for 4 points and B for 2 points)

01: version number, version 0.1

0xa0: suffix used to describe special functions.

Read more about Siemens PLC:

Siemens PLC wiring diagram physical diagram

Siemens PLC data type_ Siemens PLC communication mode

Siemens PLC program download steps

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