PLC technology, as an important technology in modern industrial control, is widely used in all walks of life and in all aspects

of production, and has received widespread attention and importance. Along with the depth of the application field, the

price of PLC systems is becoming more and more the focus of attention, effectively controlling the cost of the system will

greatly promote the popularity of this technology. Combined with the application of practice from the hardware and soft-

ware wo spects of reducing the cost of the PLC system, introduced some design skills, and with the principle of wiring dia-

grams and adder diagrams in different forms to make specific analysis, these skills in the application of PLC system, has a

good practical value.

First, the need to reduce costs

PLC as a new, universal automatic control device, with strong functions, high reliability, flexible and convenient to use, easy

to program and industrial environment adaptability and many other characteristics. Therefore, in industrial automation,

mechatronic and traditional industrial technology transformation and other aspects of the application is becoming more

and more  widespread, has become one of the three pillar of modern industrial control.

With the continuous improvement of PLC products and the development of network technology, PLC in the field of produ-

ction has also started to develop in the direction of networking, and a large number of PLCs are used in various aspects of

enterpriseproduction; in this context, the price of PLC products and the cost of the control system have become the focus

of attention of enterprises, which will also fundamentally affect the promotion of the application of PLC technology; based

on this, this paper provides some simple design techniques that can To a certain extent, this article provides some simple

esign techniques that can reduce costs and promote the widespread use of PLC.

In the actual use of PLCs, the cost of I/O points takes up a lot of money, and the average price of each point of a current PLC

can be hundreds of dollars, with imported models costing up to a thousand dollars. Reduce the number of I/O points

required is the main measure to reduce the cost of the system hardware, in most cases, the object to be controlled by the

output points less than the input points, to achieve the control task requires more detection points, or the need to operate

more buttons, so that in the selection of the number of PLC output points easier to meet the requirements of the input points

may not be easy to meet.

Therefore, the reduction in the number of I/O points is mainly in reducing the number of input points, if you can reduc the

overhead of input points, you can well reduce the cost.

The below PLC parts will you need?  Contact with Vivi (sh_plc@163.com).  

B&R X20AO2632 ANALOG OUTPUT MODULE

Siemens 6ES7221-1BH22-0XA8 SIMATIC Digital Input EM 221

Allen Bradley 1762-OW8 8 Point VAC/VDC Relay Output Module,

Siemens 6ES7541-1AB00-0AB0 SIEMENS S7 1500 Communication Module