ICST08A9 ABB _ runsheng

ICST08A9 ABB

Fast running speed

With the application of microprocessor, the running speed of PLC is increased, so that it is in line with the processing of high speed complex control tasks, the difference between it and the microcomputer is not very obvious.

8. Low total price

PLC weight, volume, power consumption and hardware prices have been reduced, although the proportion of software prices has increased, but manufacturers in order to compete also reduced prices accordingly. In addition, the use of PLC can also greatly shorten the design, programming and production cycle, so that the total price is further reduced.

PLC system, industrial bus computer and DCS system infiltrate each other, learn from each other, and compete with each other. Promoted the progress of industry.

Facing the development of fieldbus, PLC products will be innovated again to meet the high needs of industrial and civil control.

Third, PLC communication and networking

The communication of PLC includes the communication between PLC, PLC and upper computer, and PLC and other intelligent devices. PLC system and general purpose computer can be directly or through the communication processing unit, communication adapter connected to form a network to achieve the exchange, and can form a “centralized management, decentralized control” distributed control system to meet the needs of the development of factory automation (FA) system, each PLC system or remote I/O module according to the function of their respective placed in the production site decentralized control. Then network connection is used to form a distributed network system of centralized management.

Taking SIMATIC NET as an example, in the system concept of TIA proposed by SIMATIC, the core content includes the integration of configuration and programming, data management and communication. The communication network is an important and critical component of this system, providing complete industrial communication between components and the network.

SIMATIC NET consists of three main levels:

AS-I network – the standard for sensor and actuator communication, scanning time 5ms, transmission media for unshielded twisted pair, line length of 300m, mostly 31 slave stations.

PROFIBUS – Industrial field bus, the standard for workshop level and field level, the transmission rate is up to 12m/s, the transmission media is shielded two-wire cable (9.6km long) or optical cable (90km long), and can connect to 127 slave stations.