The advantages of PLC control system compared with traditional relay control are summarized.

1. is more powerful: in addition to ordinary logic processing, it also has floating-point operation, timing, counting, analog control and other functions. At present, some powerful PLCs on the market can do complex operations, such as multidimensional data operation, matrix multiplication, vector operation and so on, in addition to the above routines.

2. Shorter response time: relay control is to complete logic control through mechanical action between contacts, while PLC integrates electronic logic, and its response speed and control accuracy are incomparable with traditional relays;

3. Less fault points: relay control through mechanical contacts will generally be unable to resist PLC because of contact damage or aging, and PLC has long been recognized as a fault-free controller in the industry;

4. The communication function is more powerful: the current industrial environment is no longer a simple single machine control or production line control, but involves multi-machine group control and large-scale process automation control, which requires extremely high communication of the controller itself, and relays simply cannot do it. Now PLC can communicate not only with the execution layers such as field working instruments and electric drives, but also with PLC, and with the upper computer and the Ethernet in the central control room.

5. There are more control objects: now, whether it is single equipment or factory control, it is far from simple logical execution. For example, many devices actually have more 4-20ma/0- 10V analog input and output processing besides simple digital input and output, and the lower executive layer is driven by frequency conversion, servo system and even hydraulic system. Of course, these customers want to do it with only one controller. However, it is worth mentioning that for hydraulic control, the mainstream way is to use special hydraulic controllers, such as Rexroth and atos, but in the emerging PLC market, there are several brands of PLC that can complete this function;

6. More convenient maintenance: If a complex control network is composed of relays, once the system fails, it will only be eliminated one by one. If the PLC fails, it can automatically diagnose the fault point and give an alarm, and the system can check the fault location and cause conveniently and quickly.

..... In fact, if you really want to elaborate, there are still many advantages, but it will be too tiring to write them down. The points summarized above are typical advantages. I hope LZ can see them clearly!