It is very convenient to use PLC to control the system. This is because: First of all, the establishment of PLC control logic is a program, and the hardware wiring is replaced by the program. Programming is more convenient than wiring, and changing the program is more convenient than changing the wiring!
Secondly, the PLC hardware is highly integrated and has been integrated into various miniaturized modules. Moreover, these modules are matched and have been serialized and standardized. Most of the modules required for various control systems are available from PLC manufacturers and can be purchased on the market. Therefore, hardware system configuration and construction are also very convenient.
Because of this, the word "co" is only available with a programmable controller. Speaking of software, its program can be edited, it is not difficult to edit. Speaking of hardware, its configuration is variable and easy to change.
Specifically, PLC has five or four aspects of convenience:
(1) Easy configuration
It can be connected to the control system to determine which PLC to use, which type, which module to use, and how many modules are required. After confirmation, go to the market to order and purchase.
(2) Easy installation
PLC hardware is simple to install and easy to assemble. The external wiring has a connector, the wiring is simple, and after the connection is completed once, when the module is replaced, the connector can be installed on the new module, and no wiring is necessary. Don't connect any internal lines, just make some necessary DIP switch settings or software settings, and compile user program to work.
(3) Easy programming
Although there are no actual relays, time relays, and counters in the PLC, these devices exist through programs (software) and system memory. Its number is unimaginable for the relay control system. Even a small PLC can have thousands of internal relays, and hundreds of time relays and counts. Moreover, the contacts of these relays can be used indefinitely. There are so many internal logic devices in PLC, users don't feel any limitation when using them. The only consideration is the entry and exit points. It doesn't matter how much the internal entry and exit points are used.
The control points of a large-scale PLC can reach more than 10,000 points, how can there be such a large realistic system? If it is not enough, it can also be controlled online without any restrictions. The PLC command system is also very rich, which can realize all kinds of switching and analog control without difficulty. The PLC also has a memory area for storing data, which can store all the information to be saved in the control process ... In short, due to the strong function of the PLC, it exerts its role in the control system. The limitation is no longer the PLC itself, but people ’s Imagination, or other hardware facilities supporting it.
The peripherals of PLC are very rich, there are many types of programmers, which are more convenient to use, and there are data monitors, which can monitor the work of PLC. There are also many softwares using PLC, not only the ladder diagram language similar to the relay circuit design, but also the BASIC language, C language, and even natural language. These also provide convenience for PLC programming.
PLC programs are also easy to store, transplant and reuse. After the PLC program for a certain shaped product is perfected, all such products can be used. One can be produced and a copy can be made. This is much easier and simpler than wiring and debugging the relay circuit equipment.
(4) Easy maintenance
This is because:
â‘ PLC works reliably, and there are not many failures, which greatly reduces the maintenance workload. This will be further introduced when talking about the third feature of PLC.
â‘¡Even if the PLC fails, maintenance is very convenient. This is because PLCs are equipped with a lot of fault indication signals. For example, if the battery voltage of the PLC supporting memory to maintain data is insufficient, the corresponding low voltage signal indicates. Moreover, the PLC itself can also record fault conditions. Therefore, it is easy to diagnose the PLC failure. At the same time, it is easy to troubleshoot after diagnosing the fault. It can be sorted out by module, and the spare parts of the module can be bought in the market, and it can be replaced simply. As for the software, there will be no malfunction after debugging, as long as it is adjusted according to the use experience to make it perfect.
(5) Convenient to use: PLC is used for a certain device. If this device is no longer used, the PLC used by it can be used by other devices as long as the program is modified. If the original device differs greatly from the new device, some of its modules can be reused.
ALLIN , https://www.displayapio.com