SC-UCMX01 51307195-175 RTU2020即用型模块

SC-UCMX01 51307195-175 RTU2020即用型模块

一、PLC出产厂家的选择

承认PLC的出产厂家，主要应该考虑设备用户的要求、用户对PLC厂家的要求，规划者对PLC的了解程度和规划习气、配套产品的一致性以及技术服务等方面的因素。从PLC本身的可靠性考虑，原则上只要是国外大公司的产品，不应该存在可靠性欠好的问题。关于要求不高的，可选用高性价比的国产产品。

笔者个人以为，一般来说，关于控制独立设备或较简略的控制系统的场合，配套日本的PLC产品，也可以选择西门子的产品，因为对该产品了解的人比较多。关于系统规划较大网络通讯功用要求高、开放性的分布式控制系统、长途I/O系统，欧美出产的PLC在网络通讯功用上更有优势。

二、输入输出(I/0)点数的预算

PLC的输入/输出点数是PLC的底子参数之一。I/O点数的承认应以控制设备所需的全部输入/输出点数的总和为根据。在一般情况下，PLC的I/O点应该有恰当的余量。一般根据计算的输入输出点数，再增加30%可扩展余量。

三、PLC存储器容量的预算

存储器容量是指可编程序控制器本身能供应的硬件存储单元大小，各种PLC的存储器容量大小可以从该PLC的底子参数表中找到，例如：西门子的S7-314PLC的用户程序存储容量为64KB，S7-315-2DPPLC的用户程序存储容量为128KB。程序容量是存储器中用户程序所运用的存储单元的大小，因此存储器容量应大于程序容量。规划阶段，因为用户运用程序还未编制，因此，需求对程序容量进行预算。恰当增加容量。

SC-UCMX01 51307195-175 RTU2020即用型模块
First, the choice of PLC manufacturer

Admit that PLC manufacturers should mainly consider the requirements of equipment users, user requirements for PLC manufacturers, planners of PLC understanding and planning habits, the consistency of supporting products and technical services and other factors. From the reliability of PLC itself, in principle, as long as it is the product of a large foreign company, there should not be a problem of poor reliability. For those with low requirements, cost-effective domestic products can be selected.

The author personally believes that, in general, regarding the control of independent equipment or more simple control systems, supporting Japanese PLC products, you can also choose Siemens products, because there are more people who know about the product. As for system planning, large network communication function requirements, open distributed control system, long-distance I/O system, the PLC produced in Europe and the United States has more advantages in network communication function.

2. Budget of input and output (I/0) points

The input/output number of PLC is one of the basic parameters of PLC. The recognition of I/O points shall be based on the sum of all input/output points required to control the device. In general, the PLC's I/O points should have an appropriate margin. Generally based on the calculated input and output points, an additional 30% of the expandable margin is added.

Third, PLC memory capacity budget

Memory capacity refers to the programmable controller itself can supply the size of the hardware storage unit, the size of various PLC memory capacity can be found from the PLC base parameter table, for example: Siemens S7-314PLC user program storage capacity of 64KB, S7-315-2DPPLC user program storage capacity of 128KB. The program capacity is the size of the storage unit used by the user program in the memory, so the memory capacity should be greater than the program capacity. In the planning phase, because the user application has not yet been developed, it is necessary to budget the program capacity. Increase capacity appropriately.

SC-UCMX01 51307195-175 RTU2020即用型模块