Now the manufacturing plants, although is to raise the jobs number, but did not enlarge employment with technologies. General raise in pipeline operator number and the like are, and long working hours. So now regularly enlarge the people participation, it is because the PLC (programmable logic controller) application is a technical work, the Institute can maintain to study the future to get better them. There are a lot of PLC types now, such as Omron PLC, Mitsubishi PLC, and Siemens PLC.
These are currently the most commonly PLC, Siemens PLC in learning many people do not be familiar with Siemens S7-200 and S7-300, What is the difference, is it not the later comprise the former, they created a comparison of the below, for all hesitations.
The differences on hardware:
1. It is the vital distinction between modular of the S7-300, while S7-200 series is a monolithic, module of CPU, modules of I/O and modules of power in a module, defined as the module of CPU; the series of S7-300, from the I/O, power supply, CPU is a split module. But it is misleading to say S7-200 series can not be expanded, in actual, S7-200 can also be expanded, but bought the module of CPU incorporates some features, some small systems do not require other custom module, the module S7-200 is also a communication, signal, modules of position control.
2. S7-200 series, there is no rack concept, called the guide; in order to help the decentralized control, the modules of S7-300 series assembled in a guide rail, that is rack corresponding with the central is to expand the rack, it is also reflected in the software.
3. The modules of S7-200 series on the same rack are over the data via the module connector link and S7-300 throughout the bus at the bottom of the connector U-type connected.
4. S7-300 series of the I/O input is accepted on the first connector.