Several forms of PROFIBUS control system configuration - Database & Sql Blog Articles

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1. According to whether the field device has PROFIBUS interface, it can be divided into three forms: (1) Bus interface type: The field device does not have PROFIBUS interface, and the distributed I/O is used as the bus interface to connect with the current device. This form is easy to promote at the beginning of the application of fieldbus technology. If the field devices can be grouped and the devices in the group are relatively concentrated, this mode will give better play to the advantages of fieldbus technology.
(2) Single bus type: Field devices have PROFIBUS interface. This is an ideal situation. Fieldbus technology can be used to achieve a fully distributed architecture that fully captures the benefits of this advanced technology. If the new project can have such conditions, at present, the cost of such a scheme will be higher.
(3) Hybrid type: The field device part has a PROFIBUS interface. This will be a fairly common situation. At this time, the method of mixing PROFIBUS field devices and distributed I/O should be adopted. Whether it is an old equipment retrofit or a new project, it may not be possible to use all PROFIBUS interface field devices. Decentralized I/O can be used as a universal fieldbus interface, which is a flexible integration solution.
2, according to the actual application of several types of structures according to actual needs and funding, usually have the following types of structure:
(1) Structure type 1: A type of master station is used as a plc or controller. There is no monitoring station, but a programming device is configured during the debugging phase. This type of structure, PLC or controller complete bus communication management, slave data read and write, slave remote parameterization work.
(2) Structure type 2: A kind of main station is made by PLC or controller, and the monitoring station is connected one-to-one with PLC through serial port. This type of structure, the monitoring station is not on the PROFIBUS network, not the second class of the main station, can not directly read the slave data and complete the remote parameterization work. The slave data required by the monitoring station can only be read from the PLC controller.
(3) Structure type 3: A type of master station is used by PLC or other controllers, and the monitoring station (type 2 master station) is connected to the PROIBUS bus. This type of structure, the monitoring station as a second-class main station on the PROFIBUS network, can complete remote programming, parameterization and online monitoring functions.
(4) Structure type 4: Use a PC plus a PROFIBUS network card to make a type of primary station, and the monitoring station is integrated with a type of primary station. This is a low-cost solution, but PCs should use industrial-grade PCs with high reliability and long-term continuous operation. For this type of structure, a PC failure will cause the entire system to crash. In addition, the communication manufacturer usually only provides a template driver, and the bus control, slave control program, and monitoring program may be developed by the user, so the application development workload may be large.
(5) Structure type 5: COMOPACT COMPUTER + PROFIBUS network card + SOFTPLC structure. If the PC is replaced with a solid PC (COMOPACT COMPUTER) in the above solution, the system reliability will be greatly enhanced, which is enough to convince the user. But this is a monitoring station and a type of master station integrated controller workstation, requiring its software to complete the following functions:
· Support programming, including development, editing, and debugging of the main station application.
· Execute the application.
· Slave remote parameterization settings.
· Master/slave fault alarms and records.
· Hosting the development and debugging of monitoring programs such as device graphic monitoring screen design and database establishment.
· Equipment online graphical monitoring, data storage and statistics, reports and other functions.
Recently, a software product called SOFTPLC has emerged, which is to transform a general-purpose PC into a PLC realized by software (soft logic). This software integrates PLC programming (IEC1131) and application running functions, and graphical monitoring development and online monitoring functions of the operator monitoring station into a rugged PC to form a controller workstation with PLC and monitoring station.
(6) Structure type 6: Using a two-level network structure, this solution fully considers the needs of future expansion. For example, it is convenient to add several production lines to expand several DP networks, and to increase the number of monitoring stations in the workshop monitoring. Expand. A two-level network structure is adopted, which fully considers the expansion of the shaded part.