XMC-ZK automatic control system for coal preparation plant uses Siemens S7-400H (or S7-1500) series PLC system with redundancy function (or PLC of A-B or GE): including redundant AS-400 control station, engineer station (ES), operator station (OS), distributed I/O ET200M, PROFIBUS-DP, PROFINET network, system configuration software and industrial monitoring software.

The AS-400 control station, engineer station (ES) and operator station (OS) are all connected to the industrial Ethernet and PROFINET ring network of the system communication network. AS-400 control station exchanges data with the operator station (OS) through the system communication network. The engineer station (ES) configures, programs and debugs the AS-400 control station and the distributed I/O ET200M through the system communication network, and configures the monitoring screen of the operator station (OS). AS-400 control station exchanges data in real time with the distributed I/O ET200M through PROFIBUS-DP. AS-400 control station is the control center of the entire centralized control system. It is mainly used to realize system control functions such as monitoring the operating condition of field equipment, data acquisition and processing, automatic closed-loop circuit control, electrical equipment switching control and parameter adjustment, etc.

Engineer station (ES) includes industrial computer, industrial Ethernet card, programming software, monitoring configuration software and redundant software. Its functions are: control of system configuration, programming and debugging, configuration of monitoring screen of the operator station (OS), and composition of redundant process control station.

The operator station (OS) includes industrial computer, industrial Ethernet card, and monitoring software. Its functions are: human-machine interface, and running of the configured monitoring screen.

PROFIBUS or PROFINET is used for data exchange between field control and detection acquisition units. PROFIBUS is not only suitable for communication between automation system and field signal unit, but also suitable for the transmitters, actuators, drive devices and other field instruments and equipment that have interface and can be directly connected to acquire and monitor the field signals. It uses a twisted pair of wires to replace the large number of traditional transmission cables, thus saving substantial cable cost and also the time and cost of construction and commissioning as well as maintenance after the system is brought into operation.

Characteristics of Automatic Control System for Coal Prep Plant 

◆ High reliability and stability, and organic combination of centralized control of electromechanical equipment, production process control, production dispatching broadcast communication system and industrial video monitoring system;

◆ High speed and large capacity control station: automation control system adopts scattered control structure. The control station is set in the power distribution room, this can greatly reduce the use of control cable. Failure of a sub-station will not lead to shutdown of the whole production system, this improves the reliability of the control system. Each sub-station of control functions independently, and when malfunction occurs to some equipment under its control, immediate fault protection is provided and the upper-level computer is informed of the fault simultaneously. This improves the response speed of the system;

◆ Centralized top-to-bottom configuration mode, with conventional management functions such as report compiling and print, historic data recording and display, equipment run time statistics, etc.;

◆ Centralized and friendly human-machine interface. Prior to the centralized control system starts up (or when there is a fault), the computer interface information display system and the dispatch broadcast communication system automatically broadcast voice message and text information to remind the operators to pay attention. Safety of the system is such enhanced.

◆ Integration of equipment control and instrument detection technology greatly shortens start-up time due to the functions of centralized control of equipment, automatic detection, automatic adjustment of process parameters and automatic troubleshooting. This has increased effective production time, guarantees safe operation of equipment, enhances productivity and reduces losses;

◆ The structure of open industrial ring network allows communication with the management-level network and provides seamless connection of coal preparation plant data for smart mines.