Using PLC to achieve the control of the system is very convenient. This is because: First, the establishment of PLC control logic is a program, with the program instead of hardware wiring. Programming procedures than wiring, change the program than to change the wiring, of course, to be much more convenient!
Second, the PLC hardware is highly integrated, has been integrated into a variety of miniaturization of the module. Moreover, these modules are supporting, has achieved a series and standardization. All kinds of control system required modules, PLC manufacturers have more stock, the market can be purchased. Therefore, the hardware system configuration and construction is also very convenient.
For this reason, with the programmable controller has this "can" word. On the software, it can be compiled, it is not difficult to compile. On the hardware, its configuration is variable, but also easy to change.
Specifically, PLC has five aspects of convenience:
(1) easy to configure: the need to control the control system to determine which PLC to use, that type, what module, how many modules to determine, to the market orders can be purchased.
(2) easy installation: PLC hardware installation is simple, easy assembly. External wiring has a connector, wiring is simple, and a good connection, the replacement module, the connector can be installed on the new module, do not have to connect. Do not pick any internal lines, as long as the necessary DIP switch settings or software settings, and the preparation of a good user program can work.
(3) programming convenience: PLC internal although there is no actual relay, time relay, counter, but it through the program (software) and system memory, these devices are real there. The number of relay control system is difficult to imagine. Even a small PLC, the number of internal relays can be thousands of time relay, the count is also hundreds. Moreover, the contacts of these relays can be used indefinitely. PLC internal logic devices as much as the user does not feel any restrictions. The only thing to consider is the entry point. And this internal entry point that is used more, it does not matter. Large PLC control points up to 10,000 points above, how can there be such a big reality system? If it is not enough, but also network control, without any restrictions. PLC instruction system is also very rich, can be difficult to achieve all kinds of switch, and analog control. The PLC also has a memory area for storing data that stores all the information to be saved in the control process. ... ... In short, due to the strong PLC function, play its role in the control system, the restrictions are not PLC itself, but people's imagination, or other supporting hardware facilities.
PLC peripherals are very rich, many types of programmers, are more convenient to use, there are data monitors, PLC can monitor the work. The use of PLC software is also a lot, not only can be used similar to the relay circuit design ladder language, and some can also use the BASIC language, C language, so natural language. These also provide convenience for PLC programming.
PLC program is also easy to store, transplant and re-use. A certain type of product with the PLC after the program is perfect, where this product can be used. Produce one, copy a copy can be. This is compared to the relay circuit equipment must be wired, debugging, to save trouble and much simpler.
(4) easy maintenance: This is because:
①PLC work is reliable, there is not much trouble, which greatly reduces the workload of maintenance. This is about the third feature of PLC, will be further introduced.
② even if the PLC fails, maintenance is also very convenient. This is because the PLC has a lot of fault prompts, such as PLC support memory to keep the data of the battery voltage is insufficient, the corresponding voltage low signal indication. Moreover, the PLC itself can also be used for fault record. Therefore, PLC out of the fault, it is easy to diagnose. At the same time, the diagnosis of fault after the troubleshooting is also very simple. Can be sorted by the module, and the module of the spare parts market can be purchased, a simple replacement can be. As for the software, debugging will not be a good failure, as long as the use of experience as long as the adjustment, so that it is necessary.
(5) easy to use: PLC for a device, if the device is no longer used, and its use of the PLC can also be used to other equipment, as long as the adaptation of the program, you can do. If the original device and the new equipment is different, some of its modules can be reused.