Siemens plc learning notes 1 (S7-300 Introduction)

PLC Siemens S7-300

I have been using step 7 for a few days. Now I want to record the learning content for the system.

1. S7-300 hardware structure

S7-300 or S7-400 PLC is modular PLC, various modular independent of each other, respectively installed on the rack. Hardware structure

DI: digital input module, do: digital output module, AI: analog input module, AO: analog output module

2. S7-CPU Module

The S7-CPU module can be divided into compact, standard type, innovative type, household shape, fault safety type, special type CPU.

Cpu312c indicates a compact CPU;

CPU313C-2DP represents a compact CPU integrated with the PROFIBUS-DP protocol;

CPU314-2PtP indicates a compact CPU that integrates Point-to-Point Protocol;

Cpu313 indicates the standard type CPU;

Cpu312ifm indicates the outdoor CPU;

CPU317-2DP indicates a special type CPU integrated with the PROFIBUS-DP protocol;

3. CPU Running Mode

1) RUN-P: programmable operation module, In this mode, allows users to debug the running program.

2) Run: run mode. In this mode, only the program can be run and the program cannot be modified.

3) Stop: Stop mode. In this mode, the CPU does not execute user programs, but the computer with Step 7 can read or modify user programs.

4) MREs: memory reset mode. When the switch is released at this position, it will automatically return to the stop position, which cannot be saved.

4. S7-300PLC Functions

1) high-speed command processing.

2) Man-Machine Interface (HMI ).

3) diagnosis function.

4) password protection.

5. S7-300 module (Multi-rack diagram)

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MPI is short for multi point interface. It is a secure protocol developed by Siemens for communication between PLC. MPI communication is a simple and economical communication method when the communication speed is not high and the data volume is not large. MPI communication can use PLC S7-200/300/400, Operation Panel TP/OP and host MPI/PROFIBUS communication card, such as cp5512/CP5611/cp5613 data exchange. The communication rate of the MPI network is 19.2kbps ~ 12 Mbps, up to 32 nodes can be connected, the maximum communication distance is 50 m, but the length can be extended through repeater.

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6. S7-300 digital module address Determination

1) Each slot of the digital I/O module occupies 4B (equal to 32 I/O points). For example, the slot 1 address is 0.0 ~ 3.7; the address of the input and output points in the digit Volume Module is composed of the byte part and the bit part, for example, i0.0. For details, refer:

2) Each slot of the analog I/O module occupies 16 B (equal to 8 analog channels). The address of each analog input channel and output channel is always a word address, for example, the slot 1-the address of analog 1 is 00 ~ 01, slot 1-address of analog quantity 2: 02 ~ 03. Slot 1-address of analog quantity 8: 14 ~ 15.

Siemens plc learning notes 1 (S7-300 Introduction)