SIEMENS Programmable Logic Controller (PLC) S7 300 Objectives Learning automation system using S7 300 Learning how to configure and operate S7 300 Learning basic instructions using ladder diagram with SIMATIC Step 7 as programming software for S7 300 Equipments A set of computer equipped with SIMATIC Step 7 software S7 300 training module S7 300 with 312C CPU Figure 1 Hardware/software requirement for S7 300 Introduction Automation system is a process by which the system is expected to work on the effectiveness and efficiency of the value of time, human labor and so on, easy in operation and produce a good outcome process. To realize the above, it is used a so-called control programming PLC (Programmable Logic Controller). PLC is define as a digital electronic device that uses programmable memory to store instructions and to implement specific functions such as logic, sequence, timing, counting, and arithmetic to control various machines and processes. The major players in the PLC market is like Siemens. One of Siemens s PLC Product is S7 300 family. The S7-300 has a modular design. You can set up your own individual system by combining components from a comprehensive range of S7 300 modules. The range of modules includes the following components: CPUs for various performance ranges Signal modules for digital and analog input/output Function modules for technological functions CP (communication processors) Load power supply modules for connecting the S7-300 to 120/230V AC power supplies Interface modules for the interconnection of racks in multi-rack installations 1
All of the S7-300 modules are contained in housings protected to IP 20, i.e. they are encapsulated and can be operated without a fan. Figure 2 S7 300 Hardware Several S7-300s can communicate together and with other SIMATIC S7 PLCs via PROFIBUS bus cables. You require a programming device (PG) to program the S7-300. You hook the programming device up to the S7-300 with a special programming device cable. Experiments Several Steps for Creating a Program in Step 7 Here will be explain the principle procedure using a very brief example : Setting up a STEP 7 project Creating hardware configuration for the 312C CPU (312-5BD01-0AB0) Writing a STEP 7 program Testing the program Setting up a STEP 7 Project 1. Connect all of the equipments as in Figure 1. 2. The central tool in STEP 7 is called 'SIMATIC Manager', which is started by doubleclick on the icon of STEP 7 ( Start All Program Siemens Automation SIMATIC SIMATIC Manager) 3. STEP 7 programs are managed in projects. Such a project will now be set up (Click menu File New). 4. The project is now assigned the name 'CPU312C' under 'Name' ( CPU312C OK) 5. A 'SIMATIC 300-Station' station is now inserted. ( Insert Station SIMATIC 300 Station) 6. Click Option Set PG/PC Interface and click PC Adapter (MPI) if you want to connect with the hardware directly as shown in Figure 3 or click PLCSIM (MPI) if you want to simulate your program without real hardware finish it by clicking OK 2
Figure 3 Communication setting 7. Open the configuration tool by double-click on 'Hardware'. ( Hardware) 8. Open the hardware catalog by clicking on the symbol. ( ) The catalog is divided into the following directories: PROFIBUS-DP/PA, SIMATIC 300, SIMATIC 400 and SIMATIC PC Based Control and provides you with all the module racks, modules and interface modules for designing your hardware configuration. 9. Insert a rail by double-clicking on 'Rail' ( SIMATIC 300 RACK-300 Rail). A configuration table for designing Rack 0 is then displayed. 10. From the hardware catalog, you now can select any of the modules that are also plugged into the real rack and insert them in the configuration table. To do this, you must click on the name of the respective module, hold down the mouse button and drag the module into a row of the configuration table using the Drag & Drop function. 11. In the next step, we drag the CPU 312C onto the second slot. When this is being done, the order number and the version of the CPU can be read on the front of the CPU. ( SIMATIC 300 CPU-300 CPU 312C order number : 6ES7-312-5BD01-0AB0) 12. In the following dialog box, we now want to set up the integrated PROFIBUS interface. Because we will not use the interface here, we accept the settings with 'OK' (OK). Slot No. 3 is reserved for interface modules and therefore remains empty. Other modules which are not interface modules (IM) are therefore placed on slots 4 to 11. Add analog I/O module by drag and drop SM 334 AI4/AO2x12bit (read the suitable order number in module), as shown in Figure 4. Figure 4 Hardware Configuration 3
13. The properties of some modules can be altered ( Click on module Change properties OK). For example, a clock memory can be specified for all CPUs ( Cycle/Clock memory Clock memory Memory Byte 100). 14. If you want default addressing just skip this step. With most S7-300 CPUs, the addresses of the I/O modules can be altered. This is done by double-clicking on the corresponding modules and altering their settings in the 'Addresses' tab. A note should always be made of these addresses (addresses assigned automatically are usually tied to a specific slot). ( DI24/DO16 Addresses Deselect System Default 0 Deselect System Default 0 OK). 15. By clicking on the and buttons, the configuration table is now first stored and converted, and then loaded into the PLC. When this is being done, the key switch on the CPU should be in the Stop position! ( ) Writing a STEP 7 Program 16. In the 'SIMATIC Manager', mark the 'Blocks' folder.( SIMATIC Manager Blocks) 17. In the SIMATIC Manager, double-click on the 'OB1' block to open it ( OB1) 18. As an option, you can enter the properties of the OB1 for documentation purposes and accept them with 'OK'. ( OK) 19. LAD/STL/FDB Program S7 Blocks is an editor which allows you to create your STEP 7 program as you require. To this end, the OB1 organization block with the first network has already been opened. In order to create your first logic operations, you must mark the first network. Now you can write your first STEP 7 program. Individual programs are usually divided into networks in STEP 7. You open a new network by clicking on the network symbol, Testing The Step 7 program The STEP 7 program to be tested can now be loaded into the PLC. In our case, this is only OB1. 20. Save the organization block with and load it into the PLC by clicking on. When this is being done, the key switch on the CPU should be in the STOP position! ( ) 21. To start the program, move the key switch to the RUN position. Click on the symbol to view the program in 'OB1'. Position Description Comments Run Run Mode The CPU is processing user program Stop Stop Mode The CPU is not processing user program MRES Memory Reset Button position of the operating mode switch for a memory reset of the CPU. A CPU memory reset requires a 4
specific operating sequence (refer to the installation manual) For getting familiar with this device please try several programs below. Program 1 Program 2 Program 3 References Everything you want to know about S7 300 or SIEMENS product, please visit : https://support.industry.siemens.com/cs/?lc=en-us and enter your keyword in search box 5