Medium-sized PLC: Siemens, Schneider, Omron, Mitsubishi.
Small PLC: Siemens, Omron, Mitsubishi, LS, Panasonic, Fuji. ....
PLC control system, programmable logic controller, a digital operation electronic equipment specially designed for industrial production. It uses a programmable memory to store programs, perform logical operations, sequence control, timing, counting and arithmetic operations and other user-oriented instructions, and controls various types of machines or production processes through digital or analog input/output.
There is a website called "Industrial Control 365". You can Baidu it. There are hundreds of PLC learning books in it.
In a broad sense, "brand" is an intangible asset with economic value, and its differences are expressed through abstract, unique and recognizable mental concepts, thus occupying a certain position in people's consciousness as a comprehensive reflection. Brand building is long-term.
In a narrow sense, "brand" is a kind of "standard" or "rule" with both internal and external characteristics. It is the general name of an identification system that makes it unique, valuable, long-term and cognitive by standardizing the concept, behavior, vision and hearing.