Implementation of Blast Furnace Gas Water Spray Cooling Cont(3)

IV. REMOTE COMMUNICATION PRINCIPLE OF THE SYSTEM 4.1 Introduction of OPC

OLE is short for object linking and embedding. OPC (OLE for Process Control) is a standardized, vendor-independent software interface. It is an open and interoperable interface standard which is developed from Windows COM (Component Object Model), DCOM (Distributed COM) and XML (Extensible Markup Language). The equipment is very simple, containing at least one OPC server and one OPC client. Applying OPC server can provide data for the OPC client, and the OPC client retrieves data to make further processing. WinCC can communicate with any PLC using OPC [1]. 4.2 Communication Between OPC Server and WinCC PLC Data communication is made through PROFIBUS DP. The system collects PLC data by way of OPC data acquisition, and then WinCC reads data of OPC server as OPC client [2]. CPU226 provides two RS485 interfaces which can communicate with both PC and touch panel at the same time. CP5611 communicates with S7 PROFIBUS DP by WinCC. It generally uses S7 protocol in DP link, built-in drive, direct support, and can connect 8 PLC [3].

KEPSeverExV4.0 is installed in IPC, equipped with CP5611. Configure PC station CP card as the host station and the device supporting PROFIBUS DP protocol is the slave station. Open KEPServerEx, select appropriate communication protocol to create a new channel, establish corresponding equipment in the channel, and finally create the required variables under the equipment, as shown in figure 7. Open WinCC document by WinCC Explore, import KEP variables, and add variables to variable manager [4]

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Figure4. Temperature control adjustment diagram.

III. STATE DIAGRAM OF THE SYSTEM

There are two working ways-local control and remote control, which locate in the main control cabinet and remote IPC separately. The local control operation interface is displayed by Siemens touch panel, as shown in figure 5, and

the remote control operation interface is shown in figure 6.

Figure5. Touch panel HMI main menu screen.

There are automatic control and manual control in both local and remote control methods, which is convenient to use the device for the debugging workers and operators.

Figure6. Remote IPC system operating main screen

Figure7. KEPSeverExV4.0 variables

4.3 Data Displayed by Remote IPC

The real-time operation data recorded by WinCC is shown in figure 8, and the record illustrates that the effect of the cooling has been well satisfied the process requirements.